LCOV - code coverage report
Current view: top level - src - input_cp2k_mp2.F (source / functions) Hit Total Coverage
Test: CP2K Regtests (git:2fce0f8) Lines: 778 778 100.0 %
Date: 2024-12-21 06:28:57 Functions: 25 25 100.0 %

          Line data    Source code
       1             : !--------------------------------------------------------------------------------------------------!
       2             : !   CP2K: A general program to perform molecular dynamics simulations                              !
       3             : !   Copyright 2000-2024 CP2K developers group <https://cp2k.org>                                   !
       4             : !                                                                                                  !
       5             : !   SPDX-License-Identifier: GPL-2.0-or-later                                                      !
       6             : !--------------------------------------------------------------------------------------------------!
       7             : 
       8             : ! **************************************************************************************************
       9             : !> \brief input section for MP2
      10             : !> \par History
      11             : !>      05.2011 created
      12             : !> \author MDB
      13             : ! **************************************************************************************************
      14             : MODULE input_cp2k_mp2
      15             :    USE bibliography, ONLY: &
      16             :       Bates2013, DelBen2012, DelBen2013, DelBen2015, DelBen2015b, Rybkin2016, Wilhelm2016a, &
      17             :       Wilhelm2016b, Wilhelm2017, Wilhelm2018, Stein2022, Stein2024, Bussy2023
      18             :    USE cp_eri_mme_interface, ONLY: create_eri_mme_section
      19             :    USE cp_output_handling, ONLY: add_last_numeric, &
      20             :                                  cp_print_key_section_create, &
      21             :                                  debug_print_level, &
      22             :                                  high_print_level, &
      23             :                                  low_print_level, &
      24             :                                  medium_print_level, &
      25             :                                  silent_print_level
      26             :    USE cp_units, ONLY: cp_unit_to_cp2k
      27             :    USE input_constants, ONLY: &
      28             :       bse_fulldiag, bse_iterdiag, bse_tda, bse_abba, bse_both, &
      29             :       bse_screening_w0, bse_screening_tdhf, bse_screening_rpa, bse_screening_alpha, &
      30             :       bse_iter_both_cond, bse_iter_en_cond, bse_iter_res_cond, bse_singlet, &
      31             :       bse_triplet, do_eri_gpw, do_eri_mme, do_eri_os, do_potential_coulomb, do_potential_id, &
      32             :       do_potential_long, do_potential_mix_cl, do_potential_short, do_potential_truncated, &
      33             :       do_potential_tshpsc, eri_default, gaussian, gw_no_print_exx, gw_pade_approx, gw_print_exx, &
      34             :       gw_read_exx, gw_skip_for_regtest, gw_two_pole_model, kp_weights_W_auto, &
      35             :       kp_weights_W_tailored, kp_weights_W_uniform, mp2_method_direct, mp2_method_gpw, &
      36             :       mp2_method_none, numerical, ot_precond_full_all, ot_precond_full_kinetic, &
      37             :       ot_precond_full_single, ot_precond_full_single_inverse, ot_precond_none, &
      38             :       ot_precond_s_inverse, ri_default, ri_rpa_g0w0_crossing_bisection, &
      39             :       ri_rpa_g0w0_crossing_newton, ri_rpa_g0w0_crossing_z_shot, soc_lda, soc_none, soc_pbe, &
      40             :       wfc_mm_style_gemm, wfc_mm_style_syrk, z_solver_cg, z_solver_pople, z_solver_richardson, &
      41             :       z_solver_sd, rpa_exchange_none, rpa_exchange_axk, rpa_exchange_sosex, G0W0, evGW0, evGW, &
      42             :       sigma_none, sigma_PBE0_S1, sigma_PBE0_S2, sigma_PBE_S1, sigma_PBE_S2
      43             :    USE input_cp2k_hfx, ONLY: create_hfx_section
      44             :    USE input_cp2k_kpoints, ONLY: create_kpoint_set_section
      45             :    USE input_keyword_types, ONLY: keyword_create, &
      46             :                                   keyword_release, &
      47             :                                   keyword_type
      48             :    USE input_section_types, ONLY: section_add_keyword, &
      49             :                                   section_add_subsection, &
      50             :                                   section_create, &
      51             :                                   section_release, &
      52             :                                   section_type
      53             : 
      54             :    USE input_val_types, ONLY: char_t, &
      55             :                               integer_t, &
      56             :                               logical_t, &
      57             :                               real_t
      58             :    USE kinds, ONLY: dp
      59             :    USE string_utilities, ONLY: newline, &
      60             :                                s2a
      61             : #include "./base/base_uses.f90"
      62             : 
      63             :    IMPLICIT NONE
      64             :    PRIVATE
      65             : 
      66             :    CHARACTER(len=*), PARAMETER, PRIVATE :: moduleN = 'input_cp2k_mp2'
      67             : 
      68             :    PUBLIC :: create_mp2_section
      69             : 
      70             : CONTAINS
      71             : 
      72             : ! **************************************************************************************************
      73             : !> \brief creates the input section for the mp2 part
      74             : !> \param section the section to create
      75             : !> \author MDB
      76             : ! **************************************************************************************************
      77       64282 :    SUBROUTINE create_mp2_section(section)
      78             :       TYPE(section_type), POINTER                        :: section
      79             : 
      80             :       TYPE(keyword_type), POINTER                        :: keyword
      81             :       TYPE(section_type), POINTER                        :: print_key, subsection
      82             : 
      83       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
      84             :       CALL section_create(section, __LOCATION__, name="WF_CORRELATION", &
      85             :                           description="Sets up the wavefunction-based correlation methods as MP2, "// &
      86             :                           "RI-MP2, RI-SOS-MP2, RI-RPA and GW (inside RI-RPA). ", &
      87             :                           n_keywords=4, n_subsections=7, repeats=.TRUE., &
      88             :                           citations=(/DelBen2012, DelBen2013, DelBen2015, DelBen2015b, Rybkin2016, &
      89             :                                       Wilhelm2016a, Wilhelm2016b, Wilhelm2017, Wilhelm2018, Stein2022, &
      90      835666 :                                       Stein2024, Bussy2023/))
      91             : 
      92       64282 :       NULLIFY (keyword, subsection)
      93             : 
      94             :       CALL keyword_create( &
      95             :          keyword, __LOCATION__, &
      96             :          name="MEMORY", &
      97             :          description="Maximum allowed total memory usage during MP2 methods [MiB].", &
      98             :          usage="MEMORY 1500 ", &
      99       64282 :          default_r_val=1.024E+3_dp)
     100       64282 :       CALL section_add_keyword(section, keyword)
     101       64282 :       CALL keyword_release(keyword)
     102             : 
     103             :       CALL keyword_create( &
     104             :          keyword, __LOCATION__, &
     105             :          name="E_GAP", &
     106             :          description="Gap energy for integration grids in Hartree. Defaults to -1.0 (automatic determination). "// &
     107             :          "Recommended to set if several RPA or SOS-MP2 gradient calculations are requested or to be restarted. "// &
     108             :          "In this way, differences of integration grids across different runs are removed as CP2K "// &
     109             :          "does not include derivatives thereof.", &
     110             :          usage="E_GAP  0.5", &
     111       64282 :          default_r_val=-1.0_dp)
     112       64282 :       CALL section_add_keyword(section, keyword)
     113       64282 :       CALL keyword_release(keyword)
     114             : 
     115             :       CALL keyword_create( &
     116             :          keyword, __LOCATION__, &
     117             :          name="E_RANGE", &
     118             :          description="Energy range (ratio of largest and smallest) energy difference "// &
     119             :          "of unoccupied and occupied orbitals for integration grids. Defaults to 0.0 (automatic determination). "// &
     120             :          "Recommended to set if several RPA or SOS-MP2 gradient calculations are requested or to be restarted. "// &
     121             :          "In this way, differences of integration grids across different runs are removed as CP2K "// &
     122             :          "does not include derivatives thereof.", &
     123             :          usage="E_RANGE  10.0", &
     124       64282 :          default_r_val=-1.0_dp)
     125       64282 :       CALL section_add_keyword(section, keyword)
     126       64282 :       CALL keyword_release(keyword)
     127             : 
     128             :       CALL keyword_create( &
     129             :          keyword, __LOCATION__, &
     130             :          name="SCALE_S", &
     131             :          description="Scaling factor of the singlet energy component (opposite spin, OS) of the "// &
     132             :          "MP2, RI-MP2 and SOS-MP2 correlation energy. ", &
     133             :          usage="SCALE_S  1.0", &
     134       64282 :          default_r_val=1.0_dp)
     135       64282 :       CALL section_add_keyword(section, keyword)
     136       64282 :       CALL keyword_release(keyword)
     137             : 
     138             :       CALL keyword_create( &
     139             :          keyword, __LOCATION__, &
     140             :          name="SCALE_T", &
     141             :          description="Scaling factor of the triplet energy component (same spin, SS) of the MP2 "// &
     142             :          "and RI-MP2 correlation energy.", &
     143             :          usage="SCALE_T  1.0", &
     144       64282 :          default_r_val=1.0_dp)
     145       64282 :       CALL section_add_keyword(section, keyword)
     146       64282 :       CALL keyword_release(keyword)
     147             : 
     148             :       CALL keyword_create( &
     149             :          keyword, __LOCATION__, &
     150             :          name="GROUP_SIZE", &
     151             :          variants=(/"NUMBER_PROC"/), &
     152             :          description="Group size used in the computation of GPW and MME integrals and the MP2 correlation energy. "// &
     153             :          "The group size must be a divisor of the total number of MPI ranks. "// &
     154             :          "A smaller group size (for example the number of MPI ranks per node) "// &
     155             :          "accelerates the computation of integrals but a too large group size increases communication costs. "// &
     156             :          "A too small group size may lead to out of memory.", &
     157             :          usage="GROUP_SIZE 2", &
     158      128564 :          default_i_val=1)
     159       64282 :       CALL section_add_keyword(section, keyword)
     160       64282 :       CALL keyword_release(keyword)
     161             : 
     162       64282 :       NULLIFY (subsection)
     163       64282 :       CALL create_mp2_details_section(subsection)
     164       64282 :       CALL section_add_subsection(section, subsection)
     165       64282 :       CALL section_release(subsection)
     166             : 
     167       64282 :       CALL create_ri_mp2(subsection)
     168       64282 :       CALL section_add_subsection(section, subsection)
     169       64282 :       CALL section_release(subsection)
     170             : 
     171       64282 :       CALL create_ri_rpa(subsection)
     172       64282 :       CALL section_add_subsection(section, subsection)
     173       64282 :       CALL section_release(subsection)
     174             : 
     175       64282 :       CALL create_ri_laplace(subsection)
     176       64282 :       CALL section_add_subsection(section, subsection)
     177       64282 :       CALL section_release(subsection)
     178             : 
     179             :       ! here we generate an imag. time subsection to use with RPA or Laplace-SOS-MP2
     180       64282 :       CALL create_low_scaling(subsection)
     181       64282 :       CALL section_add_subsection(section, subsection)
     182       64282 :       CALL section_release(subsection)
     183             : 
     184       64282 :       CALL create_ri_section(subsection)
     185       64282 :       CALL section_add_subsection(section, subsection)
     186       64282 :       CALL section_release(subsection)
     187             : 
     188       64282 :       CALL create_integrals_section(subsection)
     189       64282 :       CALL section_add_subsection(section, subsection)
     190       64282 :       CALL section_release(subsection)
     191             : 
     192       64282 :       CALL create_canonical_gradients(subsection)
     193       64282 :       CALL section_add_subsection(section, subsection)
     194       64282 :       CALL section_release(subsection)
     195             : 
     196       64282 :       NULLIFY (print_key)
     197             :       CALL cp_print_key_section_create(print_key, __LOCATION__, "PRINT", &
     198             :                                        description="Controls the printing basic info about WFC methods", &
     199       64282 :                                        print_level=low_print_level, add_last=add_last_numeric, filename="__STD_OUT__")
     200       64282 :       CALL section_add_subsection(section, print_key)
     201       64282 :       CALL section_release(print_key)
     202             : 
     203       64282 :    END SUBROUTINE create_mp2_section
     204             : 
     205             : ! **************************************************************************************************
     206             : !> \brief ...
     207             : !> \param section ...
     208             : ! **************************************************************************************************
     209       64282 :    SUBROUTINE create_mp2_details_section(section)
     210             :       TYPE(section_type), POINTER                        :: section
     211             : 
     212             :       TYPE(keyword_type), POINTER                        :: keyword
     213             : 
     214       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
     215             :       CALL section_create(section, __LOCATION__, name="MP2", &
     216             :                           description="Parameters influencing MP2 (non-RI).", &
     217       64282 :                           n_keywords=3, n_subsections=0, repeats=.FALSE.)
     218             : 
     219       64282 :       NULLIFY (keyword)
     220             :       CALL keyword_create(keyword, __LOCATION__, name="_SECTION_PARAMETERS_", &
     221             :                           description="Activates MP2 calculations.", &
     222             :                           usage="&MP2 .TRUE.", &
     223       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
     224       64282 :       CALL section_add_keyword(section, keyword)
     225       64282 :       CALL keyword_release(keyword)
     226             : 
     227             :       CALL keyword_create( &
     228             :          keyword, __LOCATION__, &
     229             :          name="METHOD", &
     230             :          citations=(/DelBen2012, DelBen2013/), &
     231             :          description="Method that is used to compute the MP2 energy.", &
     232             :          usage="METHOD MP2_GPW", &
     233             :          enum_c_vals=s2a("NONE", "DIRECT_CANONICAL", "MP2_GPW"), &
     234             :          enum_i_vals=(/mp2_method_none, mp2_method_direct, mp2_method_gpw/), &
     235             :          enum_desc=s2a("Skip MP2 calculation.", &
     236             :                        "Use the direct mp2 canonical approach.", &
     237             :                        "Use the GPW approach to MP2."), &
     238      192846 :          default_i_val=mp2_method_direct)
     239       64282 :       CALL section_add_keyword(section, keyword)
     240       64282 :       CALL keyword_release(keyword)
     241             : 
     242             :       CALL keyword_create( &
     243             :          keyword, __LOCATION__, &
     244             :          name="BIG_SEND", &
     245             :          description="Influencing the direct canonical MP2 method: Send big "// &
     246             :          "messages between processes (useful for >48 processors).", &
     247             :          usage="BIG_SEND", &
     248             :          default_l_val=.TRUE., &
     249       64282 :          lone_keyword_l_val=.TRUE.)
     250       64282 :       CALL section_add_keyword(section, keyword)
     251       64282 :       CALL keyword_release(keyword)
     252             : 
     253       64282 :    END SUBROUTINE create_mp2_details_section
     254             : 
     255             : ! **************************************************************************************************
     256             : !> \brief ...
     257             : !> \param section ...
     258             : ! **************************************************************************************************
     259       64282 :    SUBROUTINE create_ri_mp2(section)
     260             :       TYPE(section_type), POINTER                        :: section
     261             : 
     262             :       TYPE(keyword_type), POINTER                        :: keyword
     263             : 
     264       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
     265             :       CALL section_create(section, __LOCATION__, name="RI_MP2", &
     266             :                           description="Parameters influencing the RI-MP2 method. RI-MP2 supports gradients.", &
     267             :                           n_keywords=3, n_subsections=1, repeats=.FALSE., &
     268      128564 :                           citations=(/DelBen2013/))
     269             : 
     270       64282 :       NULLIFY (keyword)
     271             :       CALL keyword_create(keyword, __LOCATION__, name="_SECTION_PARAMETERS_", &
     272             :                           description="Putting the &RI_MP2 section activates RI-MP2 calculation.", &
     273             :                           usage="&RI_MP2 .TRUE.", &
     274       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
     275       64282 :       CALL section_add_keyword(section, keyword)
     276       64282 :       CALL keyword_release(keyword)
     277             : 
     278             :       CALL keyword_create(keyword, __LOCATION__, name="BLOCK_SIZE", &
     279             :                           variants=(/"MESSAGE_SIZE"/), &
     280             :                           description="Determines the blocking used for communication in RI-MP2. Larger BLOCK_SIZE "// &
     281             :                           "reduces communication but requires more memory. The default (-1) is automatic.", &
     282             :                           usage="BLOCK_SIZE 2", &
     283      128564 :                           default_i_val=-1)
     284       64282 :       CALL section_add_keyword(section, keyword)
     285       64282 :       CALL keyword_release(keyword)
     286             : 
     287             :       CALL keyword_create(keyword, __LOCATION__, name="NUMBER_INTEGRATION_GROUPS", &
     288             :                           description="Sets the number of integration groups of the communication scheme in RI-MP2. "// &
     289             :                           "Integrals will be replicated such that each integration group has all integrals available. "// &
     290             :                           "Must be a divisor of the number of subgroups (see GROUP_SIZE keyword in the WF_CORRELATION "// &
     291             :                           "section. Smaller groups reduce the communication costs but increase the memory developments. "// &
     292             :                           "If the provided value is non-positive or not a divisor of the number of subgroups, "// &
     293             :                           "the number of integration groups is determined automatically (default).", &
     294             :                           usage="NUMBER_INTEGRATION_GROUPS 2", &
     295       64282 :                           default_i_val=-1)
     296       64282 :       CALL section_add_keyword(section, keyword)
     297       64282 :       CALL keyword_release(keyword)
     298             : 
     299             :       CALL keyword_create( &
     300             :          keyword, __LOCATION__, &
     301             :          name="PRINT_DGEMM_INFO", &
     302             :          description="Print details about all DGEMM calls.", &
     303             :          lone_keyword_l_val=.TRUE., &
     304       64282 :          default_l_val=.FALSE.)
     305       64282 :       CALL section_add_keyword(section, keyword)
     306       64282 :       CALL keyword_release(keyword)
     307             : 
     308       64282 :    END SUBROUTINE create_ri_mp2
     309             : 
     310             : ! **************************************************************************************************
     311             : !> \brief ...
     312             : !> \param section ...
     313             : ! **************************************************************************************************
     314       64282 :    SUBROUTINE create_opt_ri_basis(section)
     315             :       TYPE(section_type), POINTER                        :: section
     316             : 
     317             :       TYPE(keyword_type), POINTER                        :: keyword
     318             : 
     319       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
     320             :       CALL section_create(section, __LOCATION__, name="OPT_RI_BASIS", &
     321             :                           description="Parameters influencing the optimization of the RI MP2 basis. "// &
     322             :                           "Only exponents of non-contracted auxiliary basis can be optimized. "// &
     323             :                           "An initial RI auxiliary basis has to be specified.", &
     324             :                           n_keywords=6, n_subsections=0, repeats=.FALSE., &
     325      128564 :                           citations=(/DelBen2013/))
     326       64282 :       NULLIFY (keyword)
     327             :       CALL keyword_create(keyword, __LOCATION__, name="_SECTION_PARAMETERS_", &
     328             :                           description="Putting the &OPT_RI_BASIS section activates optimization of RI basis.", &
     329             :                           usage="&OPT_RI_BASIS .TRUE.", &
     330       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
     331       64282 :       CALL section_add_keyword(section, keyword)
     332       64282 :       CALL keyword_release(keyword)
     333             : 
     334             :       CALL keyword_create(keyword, __LOCATION__, name="DELTA_I_REL", &
     335             :                           variants=(/"DI_REL"/), &
     336             :                           description="Target accuracy in the relative deviation of the amplitudes calculated with "// &
     337             :                           "and without RI approximation, (more details in Chem.Phys.Lett.294(1998)143).", &
     338             :                           usage="DELTA_I_REL  1.0E-6_dp", &
     339      128564 :                           default_r_val=1.0E-6_dp)
     340       64282 :       CALL section_add_keyword(section, keyword)
     341       64282 :       CALL keyword_release(keyword)
     342             : 
     343             :       CALL keyword_create(keyword, __LOCATION__, name="DELTA_RI", &
     344             :                           variants=(/"DRI"/), &
     345             :                           description="Target accuracy in the absolute difference between the RI-MP2 "// &
     346             :                           "and the exact MP2 energy, DRI=ABS(E_MP2-E_RI-MP2).", &
     347             :                           usage="DELTA_RI  1.0E-6_dp", &
     348      128564 :                           default_r_val=5.0E-6_dp)
     349       64282 :       CALL section_add_keyword(section, keyword)
     350       64282 :       CALL keyword_release(keyword)
     351             : 
     352             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_DERIV", &
     353             :                           variants=(/"EPS_NUM_DERIV"/), &
     354             :                           description="The derivatives of the MP2 energy with respect to the "// &
     355             :                           "exponents of the basis are calculated numerically. "// &
     356             :                           "The change in the exponent a_i employed for the numerical evaluation "// &
     357             :                           "is defined as h_i=EPS_DERIV*a_i.", &
     358             :                           usage="EPS_DERIV  1.0E-3_dp", &
     359      128564 :                           default_r_val=1.0E-3_dp)
     360       64282 :       CALL section_add_keyword(section, keyword)
     361       64282 :       CALL keyword_release(keyword)
     362             : 
     363             :       CALL keyword_create(keyword, __LOCATION__, name="MAX_ITER", &
     364             :                           variants=(/"MAX_NUM_ITER"/), &
     365             :                           description="Specifies the maximum number of steps in the RI basis optimization.", &
     366             :                           usage="MAX_ITER 100", &
     367      128564 :                           default_i_val=50)
     368       64282 :       CALL section_add_keyword(section, keyword)
     369       64282 :       CALL keyword_release(keyword)
     370             : 
     371             :       CALL keyword_create(keyword, __LOCATION__, name="NUM_FUNC", &
     372             :                           description="Specifies the number of function, for each angular momentum (s, p, d ...), "// &
     373             :                           "employed in the automatically generated initial guess. "// &
     374             :                           "This will be effective only if RI_AUX_BASIS_SET in the KIND section is not specified.", &
     375             :                           usage="NUM_FUNC {number of s func.} {number of p func.} ...", &
     376       64282 :                           n_var=-1, default_i_vals=(/-1/), type_of_var=integer_t)
     377       64282 :       CALL section_add_keyword(section, keyword)
     378       64282 :       CALL keyword_release(keyword)
     379             : 
     380             :       CALL keyword_create(keyword, __LOCATION__, name="BASIS_SIZE", &
     381             :                           description="Specifies the size of the auxiliary basis set automatically "// &
     382             :                           "generated as initial guess. This will be effective only if RI_AUX_BASIS_SET "// &
     383             :                           "in the KIND section and NUM_FUNC are not specified.", &
     384             :                           usage="BASIS_SIZE  (MEDIUM|LARGE|VERY_LARGE)", &
     385             :                           enum_c_vals=s2a("MEDIUM", "LARGE", "VERY_LARGE"), &
     386             :                           enum_i_vals=(/0, 1, 2/), &
     387       64282 :                           default_i_val=0)
     388       64282 :       CALL section_add_keyword(section, keyword)
     389       64282 :       CALL keyword_release(keyword)
     390             : 
     391       64282 :    END SUBROUTINE create_opt_ri_basis
     392             : 
     393             : ! **************************************************************************************************
     394             : !> \brief ...
     395             : !> \param section ...
     396             : ! **************************************************************************************************
     397       64282 :    SUBROUTINE create_ri_laplace(section)
     398             :       TYPE(section_type), POINTER                        :: section
     399             : 
     400             :       TYPE(keyword_type), POINTER                        :: keyword
     401             : 
     402       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
     403             :       CALL section_create(section, __LOCATION__, name="RI_SOS_MP2", &
     404             :                           description="Parameters influencing the RI-SOS-MP2-Laplace method", &
     405             :                           n_keywords=3, n_subsections=1, repeats=.FALSE., &
     406      128564 :                           citations=(/DelBen2013/))
     407             : 
     408       64282 :       NULLIFY (keyword)
     409             :       CALL keyword_create(keyword, __LOCATION__, name="_SECTION_PARAMETERS_", &
     410             :                           description="Putting the &RI_SOS_MP2 section activates RI-SOS-MP2 calculation.", &
     411             :                           usage="&RI_SOS_MP2 .TRUE.", &
     412       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
     413       64282 :       CALL section_add_keyword(section, keyword)
     414       64282 :       CALL keyword_release(keyword)
     415             : 
     416             :       CALL keyword_create( &
     417             :          keyword, __LOCATION__, name="QUADRATURE_POINTS", &
     418             :          variants=(/"LAPLACE_NUM_QUAD_POINTS"/), &
     419             :          description="Number of quadrature points for the numerical integration in the RI-SOS-MP2-Laplace method.", &
     420             :          usage="QUADRATURE_POINTS 6", &
     421      128564 :          default_i_val=5)
     422       64282 :       CALL section_add_keyword(section, keyword)
     423       64282 :       CALL keyword_release(keyword)
     424             : 
     425             :       CALL keyword_create( &
     426             :          keyword, __LOCATION__, name="NUM_INTEG_GROUPS", &
     427             :          description="Number of groups for the integration in the Laplace method. Each groups processes "// &
     428             :          "the same amount of quadrature points. It must be a divisor of the number of quadrature points and "// &
     429             :          "NUM_INTEG_GROUPS*GROUP_SIZE must be a divisor of the total number of processes. The default (-1) is automatic.", &
     430             :          usage="SIZE_INTEG_GROUP 2", &
     431       64282 :          default_i_val=-1)
     432       64282 :       CALL section_add_keyword(section, keyword)
     433       64282 :       CALL keyword_release(keyword)
     434             : 
     435       64282 :    END SUBROUTINE create_ri_laplace
     436             : 
     437             : ! **************************************************************************************************
     438             : !> \brief ...
     439             : !> \param section ...
     440             : ! **************************************************************************************************
     441       64282 :    SUBROUTINE create_canonical_gradients(section)
     442             :       TYPE(section_type), POINTER                        :: section
     443             : 
     444             :       TYPE(keyword_type), POINTER                        :: keyword
     445             :       TYPE(section_type), POINTER                        :: subsection
     446             : 
     447       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
     448             :       CALL section_create(section, __LOCATION__, name="CANONICAL_GRADIENTS", &
     449             :                           description="Parameters influencing gradient calculations of canonical RI methods. "// &
     450             :                           "Ignored if the IM_TIME section is set.", &
     451             :                           n_keywords=3, n_subsections=1, repeats=.FALSE., &
     452      321410 :                           citations=(/DelBen2015b, Rybkin2016, Stein2022, Stein2024/))
     453             : 
     454       64282 :       NULLIFY (subsection, keyword)
     455       64282 :       CALL create_cphf(subsection)
     456       64282 :       CALL section_add_subsection(section, subsection)
     457       64282 :       CALL section_release(subsection)
     458             : 
     459             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_CANONICAL", &
     460             :                           description="Threshold under which a given ij or ab pair is considered to be degenerate and "// &
     461             :                           "its contribution to the density matrix is calculated directly. "// &
     462             :                           "Ignored in case of energy-only calculation.", &
     463             :                           usage="EPS_CANONICAL 1.0E-8", type_of_var=real_t, &
     464       64282 :                           default_r_val=1.0E-7_dp)
     465       64282 :       CALL section_add_keyword(section, keyword)
     466       64282 :       CALL keyword_release(keyword)
     467             : 
     468             :       CALL keyword_create( &
     469             :          keyword, __LOCATION__, &
     470             :          name="FREE_HFX_BUFFER", &
     471             :          description="Free the buffer containing the 4 center integrals used in the Hartree-Fock exchange calculation. "// &
     472             :          "Ignored for energy-only calculations. May fail.", &
     473             :          usage="FREE_HFX_BUFFER", &
     474             :          default_l_val=.FALSE., &
     475       64282 :          lone_keyword_l_val=.TRUE.)
     476       64282 :       CALL section_add_keyword(section, keyword)
     477       64282 :       CALL keyword_release(keyword)
     478             : 
     479             :       CALL keyword_create( &
     480             :          keyword, __LOCATION__, &
     481             :          name="DOT_PRODUCT_BLKSIZE", &
     482             :          description="Dot products for the calculation of the RPA/SOS-MP2 density matrices "// &
     483             :          "are calculated in batches of the size given by this keyword. Larger block sizes "// &
     484             :          "improve the performance but reduce the numerical accuracy. Recommended block sizes are multiples of the number of "// &
     485             :          "doubles per cache line (usually 8). Ignored with MP2 gradients. Set it to -1 to prevent blocking.", &
     486       64282 :          default_i_val=-1)
     487       64282 :       CALL section_add_keyword(section, keyword)
     488       64282 :       CALL keyword_release(keyword)
     489             : 
     490             :       CALL keyword_create( &
     491             :          keyword, __LOCATION__, &
     492             :          name="MAX_PARALLEL_COMM", &
     493             :          description="Sets the maximum number of parallel communication steps of the non-blocking communication scheme. "// &
     494             :          "The number of channels is determined from the available memory. If set to a value smaller than one, "// &
     495             :          "CP2K will use all memory for communication. A value of one enforces the blocking communication scheme "// &
     496             :          "increasing the communication costs.", &
     497       64282 :          default_i_val=2)
     498       64282 :       CALL section_add_keyword(section, keyword)
     499       64282 :       CALL keyword_release(keyword)
     500             : 
     501       64282 :    END SUBROUTINE create_canonical_gradients
     502             : 
     503             : ! **************************************************************************************************
     504             : !> \brief ...
     505             : !> \param section ...
     506             : ! **************************************************************************************************
     507       64282 :    SUBROUTINE create_ri_rpa(section)
     508             :       TYPE(section_type), POINTER                        :: section
     509             : 
     510             :       TYPE(keyword_type), POINTER                        :: keyword
     511             :       TYPE(section_type), POINTER                        :: subsection
     512             : 
     513       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
     514             :       CALL section_create(section, __LOCATION__, name="RI_RPA", &
     515             :                           description="Parameters influencing RI-RPA and GW.", &
     516             :                           n_keywords=8, n_subsections=4, repeats=.FALSE., &
     517      192846 :                           citations=(/DelBen2013, DelBen2015/))
     518             : 
     519       64282 :       NULLIFY (keyword, subsection)
     520             :       CALL keyword_create(keyword, __LOCATION__, name="_SECTION_PARAMETERS_", &
     521             :                           description="Putting the &RI_RPA section activates RI-RPA calculation.", &
     522             :                           usage="&RI_RPA .TRUE.", &
     523       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
     524       64282 :       CALL section_add_keyword(section, keyword)
     525       64282 :       CALL keyword_release(keyword)
     526             : 
     527             :       CALL keyword_create( &
     528             :          keyword, __LOCATION__, &
     529             :          name="SIGMA_FUNCTIONAL", &
     530             :          description="Determine parametrization for sigma-functional", &
     531             :          usage="SIGMA_FUNCTIONAL PBE_S2", &
     532             :          enum_c_vals=s2a("NONE", "PBE0_S1", "PBE0_S2", "PBE_S1", "PBE_S2"), &
     533             :          enum_i_vals=(/sigma_none, sigma_PBE0_S1, sigma_PBE0_S2, sigma_PBE_S1, sigma_PBE_S2/), &
     534             :          enum_desc=s2a("No sigma functional calculation", &
     535             :                        "use parameters based on PBE0 with S1 set.", &
     536             :                        "use parameters based on PBE0 with S2 set.", &
     537             :                        "use parameters based on PBE with S1 set.", &
     538             :                        "use parameters based on PBE with S2 set." &
     539             :                        ), &
     540       64282 :          default_i_val=sigma_none)
     541       64282 :       CALL section_add_keyword(section, keyword)
     542       64282 :       CALL keyword_release(keyword)
     543             : 
     544             :       CALL keyword_create(keyword, __LOCATION__, name="QUADRATURE_POINTS", &
     545             :                           variants=(/"RPA_NUM_QUAD_POINTS"/), &
     546             :                           description="Number of quadrature points for the numerical integration in the RI-RPA method.", &
     547             :                           usage="QUADRATURE_POINTS 60", &
     548      128564 :                           default_i_val=40)
     549       64282 :       CALL section_add_keyword(section, keyword)
     550       64282 :       CALL keyword_release(keyword)
     551             : 
     552             :       CALL keyword_create(keyword, __LOCATION__, name="NUM_INTEG_GROUPS", &
     553             :                           description="Number of groups for the integration in the Laplace method. Each groups processes "// &
     554             :                           "the same amount of quadrature points. It must be a divisor of the number of quadrature points and "// &
     555             :                           "NUM_INTEG_GROUPS*GROUP_SIZE must be a divisor of the total number of processes. "// &
     556             :                           "The default (-1) is automatic.", &
     557             :                           usage="SIZE_INTEG_GROUP 2", &
     558       64282 :                           default_i_val=-1)
     559       64282 :       CALL section_add_keyword(section, keyword)
     560       64282 :       CALL keyword_release(keyword)
     561             : 
     562             :       CALL keyword_create(keyword, __LOCATION__, &
     563             :                           name="MM_STYLE", &
     564             :                           description="Matrix multiplication style for the Q matrix.", &
     565             :                           usage="MM_STYLE GEMM", &
     566             :                           enum_c_vals=s2a("GEMM", "SYRK"), &
     567             :                           enum_i_vals=(/wfc_mm_style_gemm, wfc_mm_style_syrk/), &
     568             :                           enum_desc=s2a("Use pdgemm: more flops, maybe faster.", &
     569             :                                         "Use pdysrk: fewer flops, maybe slower."), &
     570       64282 :                           default_i_val=wfc_mm_style_gemm)
     571       64282 :       CALL section_add_keyword(section, keyword)
     572       64282 :       CALL keyword_release(keyword)
     573             : 
     574             :       CALL keyword_create( &
     575             :          keyword, __LOCATION__, &
     576             :          name="MINIMAX_QUADRATURE", &
     577             :          variants=(/"MINIMAX"/), &
     578             :          description="Use the Minimax quadrature scheme for performing the numerical integration. "// &
     579             :          "Maximum number of quadrature point limited to 20.", &
     580             :          usage="MINIMAX_QUADRATURE", &
     581             :          default_l_val=.FALSE., &
     582      128564 :          lone_keyword_l_val=.TRUE.)
     583       64282 :       CALL section_add_keyword(section, keyword)
     584       64282 :       CALL keyword_release(keyword)
     585             : 
     586             :       CALL keyword_create( &
     587             :          keyword, __LOCATION__, &
     588             :          name="RSE", &
     589             :          variants=(/"SE"/), &
     590             :          description="Decide whether to add singles correction.", &
     591             :          usage="RSE", &
     592             :          default_l_val=.FALSE., &
     593      128564 :          lone_keyword_l_val=.TRUE.)
     594       64282 :       CALL section_add_keyword(section, keyword)
     595       64282 :       CALL keyword_release(keyword)
     596             : 
     597             :       CALL keyword_create( &
     598             :          keyword, __LOCATION__, &
     599             :          name="ADMM", &
     600             :          description="Decide whether to perform ADMM in the exact exchange calc. for RPA and/or GW. "// &
     601             :          "The ADMM XC correction is governed by the AUXILIARY_DENSITY_MATRIX_METHOD section in &DFT. "// &
     602             :          "In most cases, the Hartree-Fock exchange is not too expensive and there is no need for ADMM, "// &
     603             :          "ADMM can however provide significant speedup and memory savings in case of diffuse basis sets. "// &
     604             :          "If it is a GW bandgap calculations, RI_SIGMA_X can also be used. ", &
     605             :          usage="ADMM", &
     606             :          default_l_val=.FALSE., &
     607       64282 :          lone_keyword_l_val=.TRUE.)
     608       64282 :       CALL section_add_keyword(section, keyword)
     609       64282 :       CALL keyword_release(keyword)
     610             : 
     611             :       CALL keyword_create( &
     612             :          keyword, __LOCATION__, &
     613             :          name="SCALE_RPA", &
     614             :          description="Scales RPA energy contributions (RPA, exchange correction).", &
     615             :          usage="SCALE_RPA 1.0", &
     616       64282 :          default_r_val=1.0_dp)
     617       64282 :       CALL section_add_keyword(section, keyword)
     618       64282 :       CALL keyword_release(keyword)
     619             : 
     620             :       CALL keyword_create( &
     621             :          keyword, __LOCATION__, &
     622             :          name="PRINT_DGEMM_INFO", &
     623             :          description="Print details about all DGEMM calls.", &
     624             :          lone_keyword_l_val=.TRUE., &
     625       64282 :          default_l_val=.FALSE.)
     626       64282 :       CALL section_add_keyword(section, keyword)
     627       64282 :       CALL keyword_release(keyword)
     628             : 
     629             :       ! here we generate a hfx subsection to use in the case EXX has to be computed after RPA
     630       64282 :       CALL create_hfx_section(subsection)
     631       64282 :       CALL section_add_subsection(section, subsection)
     632       64282 :       CALL section_release(subsection)
     633             : 
     634             :       ! here we generate a G0W0 subsection to use if G0W0 is desired
     635       64282 :       CALL create_ri_g0w0(subsection)
     636       64282 :       CALL section_add_subsection(section, subsection)
     637       64282 :       CALL section_release(subsection)
     638             : 
     639             :       ! here we the RPA exchange section
     640       64282 :       CALL create_rpa_exchange(subsection)
     641       64282 :       CALL section_add_subsection(section, subsection)
     642       64282 :       CALL section_release(subsection)
     643             : 
     644       64282 :    END SUBROUTINE create_ri_rpa
     645             : 
     646             : ! **************************************************************************************************
     647             : !> \brief ...
     648             : !> \param section ...
     649             : ! **************************************************************************************************
     650       64282 :    SUBROUTINE create_rpa_exchange(section)
     651             :       TYPE(section_type), POINTER                        :: section
     652             : 
     653             :       TYPE(keyword_type), POINTER                        :: keyword
     654             : 
     655       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
     656             :       CALL section_create(section, __LOCATION__, name="EXCHANGE_CORRECTION", &
     657             :                           description="Parameters influencing exchange corrections to RPA. No gradients available.", &
     658       64282 :                           n_keywords=3, n_subsections=1, repeats=.FALSE.)
     659             : 
     660       64282 :       NULLIFY (keyword)
     661             :       CALL keyword_create(keyword, __LOCATION__, name="_SECTION_PARAMETERS_", &
     662             :                           description="Choose the kind of exchange correction.", &
     663             :                           usage="&EXCHANGE_CORRECTION AXK", &
     664             :                           enum_c_vals=s2a("NONE", "AXK", "SOSEX"), &
     665             :                           enum_i_vals=(/rpa_exchange_none, rpa_exchange_axk, rpa_exchange_sosex/), &
     666             :                           enum_desc=s2a("Apply no exchange correction.", &
     667             :                                         "Apply Approximate eXchange Kernel (AXK) correction.", &
     668             :                                         "Apply Second Order Screened eXchange (SOSEX) correction."), &
     669       64282 :                           default_i_val=rpa_exchange_none)
     670       64282 :       CALL section_add_keyword(section, keyword)
     671       64282 :       CALL keyword_release(keyword)
     672             : 
     673             :       CALL keyword_create( &
     674             :          keyword, __LOCATION__, &
     675             :          name="BLOCK_SIZE", &
     676             :          description="Choose the block size of the contraction step. Larger block sizes improve performance but "// &
     677             :          "require more memory (quadratically!, number of stored elements: $o^2\cdot N_B^2$). "// &
     678             :          "Nonpositive numbers turn off blocking.", &
     679             :          usage="BLOCK_SIZE 1", &
     680       64282 :          default_i_val=1)
     681       64282 :       CALL section_add_keyword(section, keyword)
     682       64282 :       CALL keyword_release(keyword)
     683             : 
     684             :       CALL keyword_create( &
     685             :          keyword, __LOCATION__, &
     686             :          name="USE_HFX_IMPLEMENTATION", &
     687             :          description="Use a HF-based implementation with RI_RPA%HF section. Recommended for large systems.", &
     688             :          usage="USE_HFX_IMPLEMENTATION T", &
     689       64282 :          default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
     690       64282 :       CALL section_add_keyword(section, keyword)
     691       64282 :       CALL keyword_release(keyword)
     692             : 
     693       64282 :    END SUBROUTINE create_rpa_exchange
     694             : 
     695             : ! **************************************************************************************************
     696             : !> \brief ...
     697             : !> \param section ...
     698             : ! **************************************************************************************************
     699       64282 :    SUBROUTINE create_ri_g0w0(section)
     700             :       TYPE(section_type), POINTER                        :: section
     701             : 
     702             :       TYPE(keyword_type), POINTER                        :: keyword
     703             :       TYPE(section_type), POINTER                        :: subsection
     704             : 
     705       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
     706             :       CALL section_create(section, __LOCATION__, name="GW", &
     707             :                           description="Parameters influencing GW calculations on molecules, "// &
     708             :                           "see also 'Electronic band structure from GW', "// &
     709             :                           "https://manual.cp2k.org/trunk/methods/properties/bandstructure_gw.html.", &
     710       64282 :                           n_keywords=24, n_subsections=1, repeats=.FALSE.)
     711             : 
     712       64282 :       NULLIFY (keyword, subsection)
     713             : 
     714             :       CALL keyword_create(keyword, __LOCATION__, name="_SECTION_PARAMETERS_", &
     715             :                           description="Activates GW calculations.", &
     716             :                           usage="&GW .TRUE.", &
     717       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
     718       64282 :       CALL section_add_keyword(section, keyword)
     719       64282 :       CALL keyword_release(keyword)
     720             : 
     721             :       CALL keyword_create(keyword, __LOCATION__, name="SELF_CONSISTENCY", &
     722             :                           description="Decide the level of self-consistency of eigenvalues "// &
     723             :                           "(= quasiparticle energies = single-electron energies) in GW. "// &
     724             :                           "Updates of Kohn-Sham orbitals (for example qsGW) are not implemented. "// &
     725             :                           "For details which type of eigenvalue self-consistency might be good, "// &
     726             :                           "please consult Golze, Dvorak, Rinke, Front. Chem. 2019.", &
     727             :                           usage="GW_SELF_CONSISTENCY evGW0", &
     728             :                           enum_c_vals=s2a("G0W0", "evGW0", "evGW"), &
     729             :                           enum_i_vals=(/G0W0, evGW0, evGW/), &
     730             :                           enum_desc=s2a("Use DFT eigenvalues; not update.", &
     731             :                                         "Update DFT eigenvalues in G, not in W.", &
     732             :                                         "Update DFT eigenvalues in G and W."), &
     733       64282 :                           default_i_val=G0W0)
     734       64282 :       CALL section_add_keyword(section, keyword)
     735       64282 :       CALL keyword_release(keyword)
     736             : 
     737             :       CALL keyword_create(keyword, __LOCATION__, name="CORR_MOS_OCC", &
     738             :                           variants=(/"CORR_OCC"/), &
     739             :                           description="Number of occupied MOs whose energies are corrected in GW. "// &
     740             :                           "Counting beginning from HOMO, e.g. 3 corrected occ. MOs correspond "// &
     741             :                           "to correction of HOMO, HOMO-1 and HOMO-2. Numerical effort and "// &
     742             :                           "storage of RI-G0W0 increase linearly with this number. In case you "// &
     743             :                           "want to correct all occ. MOs, insert either a negative number or "// &
     744             :                           "a number larger than the number of occ. MOs. Invoking CORR_MOS_OCC -2 "// &
     745             :                           "together with a BSE cutoff, sets a sufficiently large CORR_MOS_OCC "// &
     746             :                           "for the given BSE cutoff deduced from DFT eigenvalues.", &
     747             :                           usage="CORR_OCC 3", &
     748      128564 :                           default_i_val=10)
     749       64282 :       CALL section_add_keyword(section, keyword)
     750       64282 :       CALL keyword_release(keyword)
     751             : 
     752             :       CALL keyword_create(keyword, __LOCATION__, name="CORR_MOS_VIRT", &
     753             :                           variants=(/"CORR_VIRT"/), &
     754             :                           description="Number of virtual MOs whose energies are corrected by GW. "// &
     755             :                           "Counting beginning from LUMO, e.g. 3 corrected occ. MOs correspond "// &
     756             :                           "to correction of LUMO, LUMO+1 and LUMO+2. Numerical effort and "// &
     757             :                           "storage of RI-G0W0 increase linearly with this number. In case you "// &
     758             :                           "want to correct all virt. MOs, insert either a negative number or "// &
     759             :                           "a number larger than the number of virt. MOs. Invoking CORR_MOS_VIRT -2 "// &
     760             :                           "together with a BSE cutoff, sets a sufficiently large CORR_MOS_VIRT "// &
     761             :                           "for the given BSE cutoff deduced from DFT eigenvalues.", &
     762             :                           usage="CORR_VIRT 3", &
     763      128564 :                           default_i_val=10)
     764       64282 :       CALL section_add_keyword(section, keyword)
     765       64282 :       CALL keyword_release(keyword)
     766             : 
     767             :       CALL keyword_create(keyword, __LOCATION__, name="NUMB_POLES", &
     768             :                           description="Number of poles for the fitting. Usually, two poles are sufficient. ", &
     769             :                           usage="NUMB_POLES 2", &
     770       64282 :                           default_i_val=2)
     771       64282 :       CALL section_add_keyword(section, keyword)
     772       64282 :       CALL keyword_release(keyword)
     773             : 
     774             :       CALL keyword_create(keyword, __LOCATION__, name="OMEGA_MAX_FIT", &
     775             :                           description="Determines fitting range for the self-energy on the imaginary axis: "// &
     776             :                           "[0, OMEGA_MAX_FIT] for virt orbitals, [-OMEGA_MAX_FIT,0] for occ orbitals. "// &
     777             :                           "Unit: Hartree. Default: 0.734996 H = 20 eV. ", &
     778             :                           usage="OMEGA_MAX_FIT 0.5", &
     779       64282 :                           default_r_val=0.734996_dp)
     780       64282 :       CALL section_add_keyword(section, keyword)
     781       64282 :       CALL keyword_release(keyword)
     782             : 
     783             :       CALL keyword_create(keyword, __LOCATION__, name="CROSSING_SEARCH", &
     784             :                           description="Determines, how the self_energy is evaluated on the real axis.", &
     785             :                           usage="CROSSING_SEARCH Z_SHOT", &
     786             :                           enum_c_vals=s2a("Z_SHOT", "NEWTON", "BISECTION"), &
     787             :                           enum_i_vals=(/ri_rpa_g0w0_crossing_z_shot, &
     788             :                                         ri_rpa_g0w0_crossing_newton, ri_rpa_g0w0_crossing_bisection/), &
     789             :                           enum_desc=s2a("Calculate the derivative of Sigma and out of it Z. Then extrapolate using Z.", &
     790             :                                         "Make a Newton-Raphson fix point iteration.", &
     791             :                                         "Make a bisection fix point iteration."), &
     792       64282 :                           default_i_val=ri_rpa_g0w0_crossing_newton)
     793       64282 :       CALL section_add_keyword(section, keyword)
     794       64282 :       CALL keyword_release(keyword)
     795             : 
     796             :       CALL keyword_create(keyword, __LOCATION__, name="FERMI_LEVEL_OFFSET", &
     797             :                           description="Fermi level for occ. orbitals: e_HOMO + FERMI_LEVEL_OFFSET; "// &
     798             :                           "Fermi level for virt. orbitals: e_LUMO - FERMI_LEVEL_OFFSET. "// &
     799             :                           "In case e_homo + FERMI_LEVEL_OFFSET < e_lumo - FERMI_LEVEL_OFFSET, "// &
     800             :                           "we set Fermi level = (e_HOMO+e_LUMO)/2. For cubic-scaling GW, the Fermi level "// &
     801             :                           "is always equal to (e_HOMO+e_LUMO)/2 regardless of FERMI_LEVEL_OFFSET.", &
     802             :                           usage="FERMI_LEVEL_OFFSET 1.0E-2", &
     803       64282 :                           default_r_val=2.0E-2_dp)
     804       64282 :       CALL section_add_keyword(section, keyword)
     805       64282 :       CALL keyword_release(keyword)
     806             : 
     807             :       CALL keyword_create(keyword, __LOCATION__, name="HEDIN_SHIFT", &
     808             :                           description="If true, use Hedin's shift in G0W0, evGW and evGW0 "// &
     809             :                           "(aka scGW0). Details see in Li et al. JCTC 18, 7570 "// &
     810             :                           "(2022), Figure 1. G0W0 with Hedin's shift should give "// &
     811             :                           "similar GW eigenvalues as evGW0; at a lower "// &
     812             :                           "computational cost.", &
     813             :                           usage="HEDIN_SHIFT", &
     814             :                           default_l_val=.FALSE., &
     815       64282 :                           lone_keyword_l_val=.TRUE.)
     816       64282 :       CALL section_add_keyword(section, keyword)
     817       64282 :       CALL keyword_release(keyword)
     818             : 
     819             :       CALL keyword_create(keyword, __LOCATION__, name="EV_GW_ITER", &
     820             :                           description="Maximum number of iterations for eigenvalue "// &
     821             :                           "self-consistency cycle. The computational effort of GW scales "// &
     822             :                           "linearly with this number. In case of choosing "// &
     823             :                           "GW_SELF_CONSISTENCY EVGW, the code sets EV_GW_ITER 10.", &
     824             :                           usage="EV_GW_ITER 3", &
     825       64282 :                           default_i_val=1)
     826       64282 :       CALL section_add_keyword(section, keyword)
     827       64282 :       CALL keyword_release(keyword)
     828             : 
     829             :       CALL keyword_create(keyword, __LOCATION__, name="SC_GW0_ITER", &
     830             :                           description="Maximum number of iterations for GW0 "// &
     831             :                           "self-consistency cycle. The computational effort "// &
     832             :                           "of GW is not much affected by the number of scGW0 cycles. "// &
     833             :                           "In case of choosing "// &
     834             :                           "GW_SELF_CONSISTENCY EVGW0, the code sets SC_GW0_ITER 10.", &
     835             :                           usage="SC_GW0_ITER 3", &
     836       64282 :                           default_i_val=1)
     837       64282 :       CALL section_add_keyword(section, keyword)
     838       64282 :       CALL keyword_release(keyword)
     839             : 
     840             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_ITER", &
     841             :                           description="Target accuracy for the eigenvalue self-consistency. "// &
     842             :                           "If the G0W0 HOMO-LUMO gap differs by less than the "// &
     843             :                           "target accuracy during the iteration, the eigenvalue "// &
     844             :                           "self-consistency cycle stops. Unit: Hartree.", &
     845             :                           usage="EPS_EV_SC_ITER 0.00005", &
     846             :                           default_r_val=cp_unit_to_cp2k(value=0.00136_dp, unit_str="eV"), &
     847       64282 :                           unit_str="eV")
     848             : 
     849       64282 :       CALL section_add_keyword(section, keyword)
     850       64282 :       CALL keyword_release(keyword)
     851             : 
     852             :       CALL keyword_create(keyword, __LOCATION__, name="PRINT_EXX", &
     853             :                           description="Print exchange self-energy minus exchange correlation potential for Gamma-only "// &
     854             :                           "calculation (PRINT). For a GW calculation with k-points we use this output as "// &
     855             :                           "exchange self-energy (READ). This is a temporary solution because the hybrid MPI/OMP "// &
     856             :                           "parallelization in the HFX by Manuel Guidon conflicts with the parallelization in "// &
     857             :                           "low-scaling GW k-points which is most efficient with maximum number of MPI tasks and "// &
     858             :                           "minimum number of OMP threads. For HFX by M. Guidon, the density matrix is "// &
     859             :                           "fully replicated on every MPI rank which necessitates a high number of OMP threads per MPI "// &
     860             :                           "rank for large systems to prevent out of memory. "// &
     861             :                           "Such a high number of OMP threads would slow down the GW calculation "// &
     862             :                           "severely. Therefore, it was decided to temporarily divide the GW k-point calculation in a "// &
     863             :                           "Gamma-only HF calculation with high number of OMP threads to prevent out of memory and "// &
     864             :                           "a GW k-point calculation with 1 OMP thread per MPI rank reading the previousHF output.", &
     865             :                           usage="PRINT_EXX TRUE", &
     866             :                           enum_c_vals=s2a("TRUE", "FALSE", "READ", "SKIP_FOR_REGTEST"), &
     867             :                           enum_i_vals=(/gw_print_exx, gw_no_print_exx, gw_read_exx, gw_skip_for_regtest/), &
     868             :                           enum_desc=s2a("Please, put TRUE for Gamma only calculation to get the exchange self-energy. "// &
     869             :                                         "If 'SIGMA_X' and the corresponding values for the exchange-energy are written, "// &
     870             :                                         "the writing has been successful", &
     871             :                                         "FALSE is needed if you want to do nothing here.", &
     872             :                                         "Please, put READ for the k-point GW calculation to read the exact exchange. "// &
     873             :                                         "You have to provide an output file including the exact exchange. This file "// &
     874             :                                         "has to be named 'exx.dat'.", &
     875             :                                         "SKIP_FOR_REGTEST is only used for the GW k-point regtest where no exchange "// &
     876             :                                         "self-energy is computed."), &
     877       64282 :                           default_i_val=gw_no_print_exx)
     878       64282 :       CALL section_add_keyword(section, keyword)
     879       64282 :       CALL keyword_release(keyword)
     880             : 
     881             :       CALL keyword_create(keyword, __LOCATION__, name="PRINT_SELF_ENERGY", &
     882             :                           description="If true, print the self-energy for all levels for real energy "// &
     883             :                           "together with the straight line to see the quasiparticle energy as intersection. "// &
     884             :                           "In addition, prints the self-energy for imaginary frequencies together with the Pade fit.", &
     885             :                           usage="SELF_ENERGY", &
     886             :                           default_l_val=.FALSE., &
     887       64282 :                           lone_keyword_l_val=.TRUE.)
     888       64282 :       CALL section_add_keyword(section, keyword)
     889       64282 :       CALL keyword_release(keyword)
     890             : 
     891             :       CALL keyword_create(keyword, __LOCATION__, name="RI_SIGMA_X", &
     892             :                           description="If true, the exchange self-energy is calculated approximatively with RI. "// &
     893             :                           "If false, the Hartree-Fock implementation in CP2K is used.", &
     894             :                           usage="RI_SIGMA_X", &
     895             :                           default_l_val=.TRUE., &
     896       64282 :                           lone_keyword_l_val=.TRUE.)
     897       64282 :       CALL section_add_keyword(section, keyword)
     898       64282 :       CALL keyword_release(keyword)
     899             : 
     900             :       CALL keyword_create(keyword, __LOCATION__, name="IC_CORR_LIST", &
     901             :                           description="List of image charge correction from a previous calculation to be applied in G0W0 "// &
     902             :                           "or evGW. Keyword is active, if the first entry is positive (since IC corrections are positive "// &
     903             :                           "occupied MOs. The start corresponds to the first corrected GW level.", &
     904             :                           usage="IC_CORR_LIST <REAL> ... <REAL>", &
     905             :                           default_r_vals=(/-1.0_dp/), &
     906       64282 :                           type_of_var=real_t, n_var=-1, unit_str="eV")
     907       64282 :       CALL section_add_keyword(section, keyword)
     908       64282 :       CALL keyword_release(keyword)
     909             : 
     910             :       CALL keyword_create(keyword, __LOCATION__, name="IC_CORR_LIST_BETA", &
     911             :                           description="IC_CORR_LIST for beta spins in case of open shell calculation.", &
     912             :                           usage="IC_CORR_LIST_BETA <REAL> ... <REAL>", &
     913             :                           default_r_vals=(/-1.0_dp/), &
     914       64282 :                           type_of_var=real_t, n_var=-1, unit_str="eV")
     915       64282 :       CALL section_add_keyword(section, keyword)
     916       64282 :       CALL keyword_release(keyword)
     917             : 
     918             :       CALL keyword_create(keyword, __LOCATION__, name="PERIODIC_CORRECTION", &
     919             :                           description="If true, the periodic correction scheme is used employing k-points. "// &
     920             :                           "Method is not recommended to use, use instead PERIODIC_LOW_SCALING which much "// &
     921             :                           "more accurate than the periodic correction.", &
     922             :                           usage="PERIODIC_CORRECTION", &
     923             :                           default_l_val=.FALSE., &
     924       64282 :                           lone_keyword_l_val=.TRUE.)
     925       64282 :       CALL section_add_keyword(section, keyword)
     926       64282 :       CALL keyword_release(keyword)
     927             : 
     928             :       CALL keyword_create(keyword, __LOCATION__, name="IMAGE_CHARGE_MODEL", &
     929             :                           variants=(/"IC"/), &
     930             :                           description="If true, an image charge model is applied to mimic the renormalization of "// &
     931             :                           "electronic levels of a molecule at a metallic surface. For this calculation, the molecule "// &
     932             :                           "has to be reflected on the desired xy image plane. The coordinates of the reflected molecule "// &
     933             :                           "have to be added to the coord file as ghost atoms. For the ghost atoms, identical basis sets "// &
     934             :                           "the normal atoms have to be used.", &
     935             :                           usage="IC TRUE", &
     936             :                           default_l_val=.FALSE., &
     937      128564 :                           lone_keyword_l_val=.TRUE.)
     938       64282 :       CALL section_add_keyword(section, keyword)
     939       64282 :       CALL keyword_release(keyword)
     940             : 
     941             :       CALL keyword_create(keyword, __LOCATION__, name="ANALYTIC_CONTINUATION", &
     942             :                           description="Defines which type of analytic continuation for the self energy is used", &
     943             :                           usage="ANALYTIC_CONTINUATION", &
     944             :                           enum_c_vals=s2a("TWO_POLE", "PADE"), &
     945             :                           enum_i_vals=(/gw_two_pole_model, gw_pade_approx/), &
     946             :                           enum_desc=s2a("Use 'two-pole' model.", &
     947             :                                         "Use Pade approximation."), &
     948       64282 :                           default_i_val=gw_pade_approx)
     949       64282 :       CALL section_add_keyword(section, keyword)
     950       64282 :       CALL keyword_release(keyword)
     951             : 
     952             :       CALL keyword_create(keyword, __LOCATION__, name="NPARAM_PADE", &
     953             :                           description="Number of parameters for the Pade approximation "// &
     954             :                           "when using the latter for the analytic continuation of the "// &
     955             :                           "self energy. 16 parameters (corresponding to 8 poles) are "// &
     956             :                           "are recommended.", &
     957             :                           usage="NPARAM_PADE 16", &
     958       64282 :                           default_i_val=16)
     959       64282 :       CALL section_add_keyword(section, keyword)
     960       64282 :       CALL keyword_release(keyword)
     961             : 
     962             :       CALL keyword_create(keyword, __LOCATION__, name="GAMMA_ONLY_SIGMA", &
     963             :                           variants=(/"GAMMA"/), &
     964             :                           description="If true, the correlation self-energy is only computed at the Gamma point. "// &
     965             :                           "The Gamma point itself is obtained by averaging over all kpoints of the DFT mesh.", &
     966             :                           usage="GAMMA TRUE", &
     967             :                           default_l_val=.FALSE., &
     968      128564 :                           lone_keyword_l_val=.TRUE.)
     969       64282 :       CALL section_add_keyword(section, keyword)
     970       64282 :       CALL keyword_release(keyword)
     971             : 
     972             :       CALL keyword_create(keyword, __LOCATION__, name="UPDATE_XC_ENERGY", &
     973             :                           description="If true, the Hartree-Fock and RPA total energy are printed and the total energy "// &
     974             :                           "is corrected using exact exchange and the RPA correlation energy.", &
     975             :                           usage="UPDATE_XC_ENERGY", &
     976             :                           default_l_val=.FALSE., &
     977       64282 :                           lone_keyword_l_val=.TRUE.)
     978       64282 :       CALL section_add_keyword(section, keyword)
     979       64282 :       CALL keyword_release(keyword)
     980             : 
     981             :       CALL keyword_create(keyword, __LOCATION__, name="KPOINTS_SELF_ENERGY", &
     982             :                           description="Specify number of k-points for the k-point grid of the self-energy. Internally, a "// &
     983             :                           "Monkhorst-Pack grid is used. A dense k-point grid may be necessary to compute an accurate density "// &
     984             :                           "of state from GW. Large self-energy k-meshes do not cost much more computation time.", &
     985             :                           usage="KPOINTS  nx  ny  nz", repeats=.TRUE., &
     986       64282 :                           n_var=3, type_of_var=integer_t, default_i_vals=(/0, 0, 0/))
     987       64282 :       CALL section_add_keyword(section, keyword)
     988       64282 :       CALL keyword_release(keyword)
     989             : 
     990             :       CALL keyword_create(keyword, __LOCATION__, name="REGULARIZATION_MINIMAX", &
     991             :                           description="Tikhonov regularization for computing weights of the Fourier transform "// &
     992             :                           "from imaginary time to imaginary frequency and vice versa. Needed for large minimax "// &
     993             :                           "grids with 20 or more points and a small range.", &
     994             :                           usage="REGULARIZATION_MINIMAX 1.0E-6", &
     995       64282 :                           default_r_val=0.0_dp)
     996       64282 :       CALL section_add_keyword(section, keyword)
     997       64282 :       CALL keyword_release(keyword)
     998             : 
     999             :       CALL keyword_create(keyword, __LOCATION__, name="SOC", &
    1000             :                           description="Calculate the spin-orbit splitting of the eigenvalues/band structure "// &
    1001             :                           "using the spin-orbit part of the GTH pseudos parametrized in Hartwigsen, Goedecker, "// &
    1002             :                           "Hutter, Phys. Rev. B 58, 3641 (1998), Eq. 19, "// &
    1003             :                           "parameters in Table I.", &
    1004             :                           usage="SOC", &
    1005             :                           enum_c_vals=s2a("NONE", "LDA", "PBE"), &
    1006             :                           enum_i_vals=(/soc_none, soc_lda, soc_pbe/), &
    1007             :                           enum_desc=s2a("No SOC.", &
    1008             :                                         "Use parameters from LDA (PADE) pseudopotential.", &
    1009             :                                         "Use parameters from PBE pseudopotential."), &
    1010       64282 :                           default_i_val=soc_none)
    1011       64282 :       CALL section_add_keyword(section, keyword)
    1012       64282 :       CALL keyword_release(keyword)
    1013             : 
    1014             :       CALL keyword_create(keyword, __LOCATION__, name="SOC_ENERGY_WINDOW", &
    1015             :                           description="For perturbative SOC calculation, only "// &
    1016             :                           "take frontier levels in an energy window "// &
    1017             :                           "[E_HOMO - SOC_ENERGY_WINDOW/2 , E_LUMO + SOC_ENERGY_WINDOW/2 "// &
    1018             :                           "into account for the diagonalization of H^GW,SOC.", &
    1019             :                           usage="SOC_ENERGY_WINDOW 20.0_eV", &
    1020             :                           default_r_val=cp_unit_to_cp2k(value=50.0_dp, unit_str="eV"), &
    1021       64282 :                           unit_str="eV")
    1022       64282 :       CALL section_add_keyword(section, keyword)
    1023       64282 :       CALL keyword_release(keyword)
    1024             : 
    1025             :       ! here we generate a subsection for the periodic GW correction
    1026       64282 :       CALL create_periodic_gw_correction_section(subsection)
    1027       64282 :       CALL section_add_subsection(section, subsection)
    1028       64282 :       CALL section_release(subsection)
    1029             : 
    1030             :       ! here we generate a subsection for Bethe-Salpeter
    1031       64282 :       CALL create_bse_section(subsection)
    1032       64282 :       CALL section_add_subsection(section, subsection)
    1033       64282 :       CALL section_release(subsection)
    1034             : 
    1035             :       ! here we generate a subsection for image charge calculations
    1036       64282 :       CALL create_ic_section(subsection)
    1037       64282 :       CALL section_add_subsection(section, subsection)
    1038       64282 :       CALL section_release(subsection)
    1039             : 
    1040             :       ! here we generate a subsection for calculating the GW band structures
    1041       64282 :       CALL create_kpoint_set_section(subsection)
    1042       64282 :       CALL section_add_subsection(section, subsection)
    1043       64282 :       CALL section_release(subsection)
    1044             : 
    1045             :       ! here we generate a subsection for additional printing
    1046       64282 :       CALL create_print_section(subsection)
    1047       64282 :       CALL section_add_subsection(section, subsection)
    1048       64282 :       CALL section_release(subsection)
    1049             : 
    1050       64282 :    END SUBROUTINE create_ri_g0w0
    1051             : 
    1052             : ! **************************************************************************************************
    1053             : !> \brief ...
    1054             : !> \param section ...
    1055             : ! **************************************************************************************************
    1056       64282 :    SUBROUTINE create_print_section(section)
    1057             :       TYPE(section_type), POINTER                        :: section
    1058             : 
    1059             :       TYPE(keyword_type), POINTER                        :: keyword
    1060             :       TYPE(section_type), POINTER                        :: gw_dos_section, print_key
    1061             : 
    1062       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    1063       64282 :       NULLIFY (print_key, keyword)
    1064       64282 :       NULLIFY (gw_dos_section, keyword)
    1065             :       CALL section_create(section, __LOCATION__, name="PRINT", &
    1066             :                           description="Section of possible print options specific for the GW code.", &
    1067       64282 :                           n_keywords=0, n_subsections=2, repeats=.FALSE.)
    1068             : 
    1069             :       CALL cp_print_key_section_create(print_key, __LOCATION__, "LOCAL_BANDGAP", &
    1070             :                                        description="Prints a local bandgap E_gap(r), derived from the local density of "// &
    1071             :                                        "states rho(r,E). Details and formulae in the SI of the periodic GW paper (2023).", &
    1072             :                                        print_level=high_print_level, add_last=add_last_numeric, &
    1073             :                                        filename="LOCAL_BANDGAP", &
    1074       64282 :                                        common_iter_levels=3)
    1075             : 
    1076             :       CALL keyword_create(keyword, __LOCATION__, name="ENERGY_WINDOW", &
    1077             :                           description="Energy window in the LDOS for searching the gap.", &
    1078             :                           usage="ENERGY_WINDOW 6.0", &
    1079             :                           default_r_val=cp_unit_to_cp2k(value=6.0_dp, unit_str="eV"), &
    1080       64282 :                           unit_str="eV")
    1081       64282 :       CALL section_add_keyword(print_key, keyword)
    1082       64282 :       CALL keyword_release(keyword)
    1083             : 
    1084             :       CALL keyword_create(keyword, __LOCATION__, name="ENERGY_SPACING", &
    1085             :                           description="Energy spacing of the LDOS for searching the gap.", &
    1086             :                           usage="ENERGY_SPACING 0.03", &
    1087             :                           default_r_val=cp_unit_to_cp2k(value=0.03_dp, unit_str="eV"), &
    1088       64282 :                           unit_str="eV")
    1089       64282 :       CALL section_add_keyword(print_key, keyword)
    1090       64282 :       CALL keyword_release(keyword)
    1091             : 
    1092             :       CALL keyword_create(keyword, __LOCATION__, name="LDOS_THRESHOLD_GAP", &
    1093             :                           description="Relative LDOS threshold that determines the local bandgap.", &
    1094             :                           usage="LDOS_THRESHOLD_GAP 0.1", &
    1095       64282 :                           default_r_val=0.1_dp)
    1096       64282 :       CALL section_add_keyword(print_key, keyword)
    1097       64282 :       CALL keyword_release(keyword)
    1098             : 
    1099             :       CALL keyword_create(keyword, __LOCATION__, name="STRIDE", &
    1100             :                           description="The stride (X,Y,Z) used to write the cube file "// &
    1101             :                           "(larger values result in smaller cube files). You can provide 3 numbers (for X,Y,Z) or"// &
    1102             :                           " 1 number valid for all components.", &
    1103       64282 :                           usage="STRIDE 2 2 2", n_var=-1, default_i_vals=(/2, 2, 2/), type_of_var=integer_t)
    1104       64282 :       CALL section_add_keyword(print_key, keyword)
    1105       64282 :       CALL keyword_release(keyword)
    1106             : 
    1107       64282 :       CALL section_add_subsection(section, print_key)
    1108       64282 :       CALL section_release(print_key)
    1109             : 
    1110             :       CALL section_create(gw_dos_section, __LOCATION__, name="GW_DOS", &
    1111             :                           description="Section for printing the spectral function.", &
    1112       64282 :                           n_keywords=6, n_subsections=0, repeats=.FALSE.)
    1113             : 
    1114             :       CALL keyword_create(keyword, __LOCATION__, name="LOWER_BOUND", &
    1115             :                           description="Lower bound for GW-DOS in eV.", &
    1116             :                           usage="LOWER_BOUND -20.0", &
    1117             :                           default_r_val=cp_unit_to_cp2k(value=-20.0_dp, unit_str="eV"), &
    1118       64282 :                           unit_str="eV")
    1119       64282 :       CALL section_add_keyword(gw_dos_section, keyword)
    1120       64282 :       CALL keyword_release(keyword)
    1121             : 
    1122             :       CALL keyword_create(keyword, __LOCATION__, name="UPPER_BOUND", &
    1123             :                           description="Upper bound for GW-DOS in eV.", &
    1124             :                           usage="UPPER_BOUND 5.0", &
    1125             :                           default_r_val=cp_unit_to_cp2k(value=0.0_dp, unit_str="eV"), &
    1126       64282 :                           unit_str="eV")
    1127       64282 :       CALL section_add_keyword(gw_dos_section, keyword)
    1128       64282 :       CALL keyword_release(keyword)
    1129             : 
    1130             :       CALL keyword_create(keyword, __LOCATION__, name="STEP", &
    1131             :                           description="Difference of two consecutive energy levels for GW-DOS.", &
    1132             :                           usage="STEP 0.1", &
    1133             :                           default_r_val=cp_unit_to_cp2k(value=0.0_dp, unit_str="eV"), &
    1134       64282 :                           unit_str="eV")
    1135       64282 :       CALL section_add_keyword(gw_dos_section, keyword)
    1136       64282 :       CALL keyword_release(keyword)
    1137             : 
    1138             :       CALL keyword_create(keyword, __LOCATION__, name="MIN_LEVEL_SPECTRAL", &
    1139             :                           description="Lowest energy level to print the self energy to files.", &
    1140             :                           usage="MIN_LEVEL_SPECTRAL 3", &
    1141       64282 :                           default_i_val=1)
    1142       64282 :       CALL section_add_keyword(gw_dos_section, keyword)
    1143       64282 :       CALL keyword_release(keyword)
    1144             : 
    1145             :       CALL keyword_create(keyword, __LOCATION__, name="MAX_LEVEL_SPECTRAL", &
    1146             :                           description="Highest energy level to print the self energy to files.", &
    1147             :                           usage="MAX_LEVEL_SPECTRAL 6", &
    1148       64282 :                           default_i_val=0)
    1149       64282 :       CALL section_add_keyword(gw_dos_section, keyword)
    1150       64282 :       CALL keyword_release(keyword)
    1151             : 
    1152             :       CALL keyword_create(keyword, __LOCATION__, name="MIN_LEVEL_SELF_ENERGY", &
    1153             :                           description="Lowest energy level to print the self energy to files.", &
    1154             :                           usage="MIN_LEVEL_SELF_ENERGY 3", &
    1155       64282 :                           default_i_val=1)
    1156       64282 :       CALL section_add_keyword(gw_dos_section, keyword)
    1157       64282 :       CALL keyword_release(keyword)
    1158             : 
    1159             :       CALL keyword_create(keyword, __LOCATION__, name="MAX_LEVEL_SELF_ENERGY", &
    1160             :                           description="Highest energy level to print the self energy to files.", &
    1161             :                           usage="MAX_LEVEL_SELF_ENERGY 6", &
    1162       64282 :                           default_i_val=0)
    1163       64282 :       CALL section_add_keyword(gw_dos_section, keyword)
    1164       64282 :       CALL keyword_release(keyword)
    1165             : 
    1166             :       CALL keyword_create(keyword, __LOCATION__, name="BROADENING", &
    1167             :                           description="Broadening parameter for spectral function.", &
    1168             :                           usage="BROADENING 0.001", &
    1169             :                           default_r_val=cp_unit_to_cp2k(value=0.0_dp, unit_str="eV"), &
    1170       64282 :                           unit_str="eV")
    1171       64282 :       CALL section_add_keyword(gw_dos_section, keyword)
    1172       64282 :       CALL keyword_release(keyword)
    1173             : 
    1174       64282 :       CALL section_add_subsection(section, gw_dos_section)
    1175       64282 :       CALL section_release(gw_dos_section)
    1176             : 
    1177       64282 :    END SUBROUTINE
    1178             : 
    1179             : ! **************************************************************************************************
    1180             : !> \brief ...
    1181             : !> \param section ...
    1182             : ! **************************************************************************************************
    1183       64282 :    SUBROUTINE create_periodic_gw_correction_section(section)
    1184             :       TYPE(section_type), POINTER                        :: section
    1185             : 
    1186             :       TYPE(keyword_type), POINTER                        :: keyword
    1187             : 
    1188       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    1189             :       CALL section_create(section, __LOCATION__, name="PERIODIC_CORRECTION", &
    1190             :                           description="Parameters influencing correction for periodic GW. Old method, "// &
    1191             :                           "not recommended to use", &
    1192       64282 :                           n_keywords=12, n_subsections=1, repeats=.FALSE.)
    1193             : 
    1194       64282 :       NULLIFY (keyword)
    1195             : 
    1196             :       CALL keyword_create(keyword, __LOCATION__, name="KPOINTS", &
    1197             :                           description="Specify number of k-points for a single k-point grid. Internally, a "// &
    1198             :                           "Monkhorst-Pack grid is used. Typically, even numbers are chosen such that the Gamma "// &
    1199             :                           "point is excluded from the k-point mesh.", &
    1200             :                           usage="KPOINTS  nx  ny  nz", repeats=.TRUE., &
    1201       64282 :                           n_var=3, type_of_var=integer_t, default_i_vals=(/16, 16, 16/))
    1202       64282 :       CALL section_add_keyword(section, keyword)
    1203       64282 :       CALL keyword_release(keyword)
    1204             : 
    1205             :       CALL keyword_create(keyword, __LOCATION__, name="NUM_KP_GRIDS", &
    1206             :                           description="Number of k-point grids around the Gamma point with different resolution. "// &
    1207             :                           "E.g. for KPOINTS 4 4 4 and NUM_KP_GRIDS 3, there will be a 3x3x3 Monkhorst-Pack (MP) k-point "// &
    1208             :                           "grid for the whole Brillouin zone (excluding Gamma), another 3x3x3 MP grid with smaller  "// &
    1209             :                           "spacing around Gamma (again excluding Gamma) and a very fine 4x4x4 MP grid around Gamma.", &
    1210             :                           usage="NUM_KP_GRIDS 5", &
    1211       64282 :                           default_i_val=1)
    1212       64282 :       CALL section_add_keyword(section, keyword)
    1213       64282 :       CALL keyword_release(keyword)
    1214             : 
    1215             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_KPOINT", &
    1216             :                           description="If the absolute value of a k-point is below EPS_KPOINT, this kpoint is "// &
    1217             :                           "neglected since the Gamma point is not included in the periodic correction.", &
    1218             :                           usage="EPS_KPOINT 1.0E-4", &
    1219       64282 :                           default_r_val=1.0E-05_dp)
    1220       64282 :       CALL section_add_keyword(section, keyword)
    1221       64282 :       CALL keyword_release(keyword)
    1222             : 
    1223             :       CALL keyword_create(keyword, __LOCATION__, name="MO_COEFF_GAMMA", &
    1224             :                           description="If true, only the MO coefficients at the Gamma point are used for the periodic  "// &
    1225             :                           "correction. Otherwise, the MO coeffs are computed at every k-point which is much more "// &
    1226             :                           "expensive. It should be okay to use the Gamma MO coefficients.", &
    1227             :                           usage="MO_COEFF_GAMMA", &
    1228             :                           default_l_val=.TRUE., &
    1229       64282 :                           lone_keyword_l_val=.TRUE.)
    1230       64282 :       CALL section_add_keyword(section, keyword)
    1231       64282 :       CALL keyword_release(keyword)
    1232             : 
    1233             :       CALL keyword_create(keyword, __LOCATION__, name="AVERAGE_DEGENERATE_LEVELS", &
    1234             :                           variants=(/"ADL"/), &
    1235             :                           description="If true, the correlation self-energy of degenerate levels is averaged.", &
    1236             :                           usage="AVERAGE_DEGENERATE_LEVELS", &
    1237             :                           default_l_val=.TRUE., &
    1238      128564 :                           lone_keyword_l_val=.TRUE.)
    1239       64282 :       CALL section_add_keyword(section, keyword)
    1240       64282 :       CALL keyword_release(keyword)
    1241             : 
    1242             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_EIGENVAL", &
    1243             :                           description="Threshold for considering levels as degenerate. Unit: Hartree.", &
    1244             :                           usage="EPS_EIGENVAL 1.0E-5", &
    1245       64282 :                           default_r_val=2.0E-04_dp)
    1246       64282 :       CALL section_add_keyword(section, keyword)
    1247       64282 :       CALL keyword_release(keyword)
    1248             : 
    1249             :       CALL keyword_create(keyword, __LOCATION__, name="EXTRAPOLATE_KPOINTS", &
    1250             :                           variants=(/"EXTRAPOLATE"/), &
    1251             :                           description="If true, extrapolates the k-point mesh. Only working if k-point mesh numbers are "// &
    1252             :                           "divisible by 4, e.g. 8x8x8 or 12x12x12 is recommended.", &
    1253             :                           usage="EXTRAPOLATE_KPOINTS FALSE", &
    1254             :                           default_l_val=.TRUE., &
    1255      128564 :                           lone_keyword_l_val=.TRUE.)
    1256       64282 :       CALL section_add_keyword(section, keyword)
    1257       64282 :       CALL keyword_release(keyword)
    1258             : 
    1259             :       CALL keyword_create(keyword, __LOCATION__, name="DO_AUX_BAS_GW", &
    1260             :                           description="If true, use a different basis for the periodic correction. This can be necessary "// &
    1261             :                           "in case a diffused basis is used for GW to converge the HOMO-LUMO gap. In this case, "// &
    1262             :                           "numerical problems may occur due to diffuse functions in the basis. This keyword only works if "// &
    1263             :                           "AUX_GW <basis set>  is specified in the kind section for every atom kind.", &
    1264             :                           usage="AUX_BAS_GW TRUE", &
    1265             :                           default_l_val=.FALSE., &
    1266       64282 :                           lone_keyword_l_val=.TRUE.)
    1267       64282 :       CALL section_add_keyword(section, keyword)
    1268       64282 :       CALL keyword_release(keyword)
    1269             : 
    1270             :       CALL keyword_create(keyword, __LOCATION__, name="FRACTION_AUX_MOS", &
    1271             :                           description="Fraction how many MOs are used in the auxiliary basis.", &
    1272             :                           usage="FRACTION_AUX_MOS 0.6", &
    1273       64282 :                           default_r_val=0.5_dp)
    1274       64282 :       CALL section_add_keyword(section, keyword)
    1275       64282 :       CALL keyword_release(keyword)
    1276             : 
    1277             :       CALL keyword_create(keyword, __LOCATION__, name="NUM_OMEGA_POINTS", &
    1278             :                           description="Number of Clenshaw-Curtis integration points for the periodic correction in cubic- "// &
    1279             :                           "scaling GW. This variable is a dummy variable for canonical N^4 GW calculations.", &
    1280             :                           usage="NUM_OMEGA_POINTS 200", &
    1281       64282 :                           default_i_val=300)
    1282       64282 :       CALL section_add_keyword(section, keyword)
    1283       64282 :       CALL keyword_release(keyword)
    1284             : 
    1285       64282 :    END SUBROUTINE
    1286             : 
    1287             : ! **************************************************************************************************
    1288             : !> \brief ...
    1289             : !> \param section ...
    1290             : ! **************************************************************************************************
    1291       64282 :    SUBROUTINE create_bse_section(section)
    1292             :       TYPE(section_type), POINTER                        :: section
    1293             : 
    1294             :       TYPE(keyword_type), POINTER                        :: keyword
    1295             :       TYPE(section_type), POINTER                        :: subsection
    1296             : 
    1297       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    1298             :       CALL section_create(section, __LOCATION__, name="BSE", &
    1299             :                           description="Parameters for a calculation solving the Bethe-Salpeter equation "// &
    1300             :                           "(BSE) for electronic excitations. The full BSE "// &
    1301             :                           "$\left( \begin{array}{cc}A &  B\\B &  A\end{array} \right)$ "// &
    1302             :                           "$\left( \begin{array}{cc}\mathbf{X}^{(n)}\\\mathbf{Y}^{(n)}\end{array} \right) = "// &
    1303             :                           "\Omega^{(n)}\left(\begin{array}{cc}1&0\\0&-1\end{array}\right)$ "// &
    1304             :                           "$\left(\begin{array}{cc}\mathbf{X}^{(n)}\\\mathbf{Y}^{(n)}\end{array}\right)$ "// &
    1305             :                           "enables, for example, the computation of electronic excitation energies $\Omega^{(n)}$ "// &
    1306             :                           "as well as optical properties. The BSE can be solved by diagonalizing "// &
    1307             :                           "the full ABBA-matrix or by setting B=0, i.e. within the Tamm-Dancoff approximation (TDA). "// &
    1308             :                          "Preliminary reference: Eq. (35) in PRB 92, 045209 (2015); http://dx.doi.org/10.1103/PhysRevB.92.045209", &
    1309       64282 :                           n_keywords=8, n_subsections=3, repeats=.FALSE.)
    1310             : 
    1311       64282 :       NULLIFY (keyword)
    1312             : 
    1313             :       CALL keyword_create(keyword, __LOCATION__, name="_SECTION_PARAMETERS_", &
    1314             :                           description="Activates BSE calculations.", &
    1315             :                           usage="&BSE .TRUE.", &
    1316       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
    1317       64282 :       CALL section_add_keyword(section, keyword)
    1318       64282 :       CALL keyword_release(keyword)
    1319             : 
    1320             :       CALL keyword_create(keyword, __LOCATION__, name="SPIN_CONFIG", &
    1321             :                           description="Choose between calculation of singlet or triplet excitation (cf. given Reference above).", &
    1322             :                           usage="SPIN_CONFIG TRIPLET", &
    1323             :                           enum_c_vals=s2a("SINGLET", "TRIPLET"), &
    1324             :                           enum_i_vals=(/bse_singlet, bse_triplet/), &
    1325             :                           enum_desc=s2a("Computes singlet excitations.", &
    1326             :                                         "Computes triplet excitations."), &
    1327       64282 :                           default_i_val=bse_singlet)
    1328       64282 :       CALL section_add_keyword(section, keyword)
    1329       64282 :       CALL keyword_release(keyword)
    1330             : 
    1331             :       CALL keyword_create(keyword, __LOCATION__, name="BSE_DIAG_METHOD", &
    1332             :                           description="Method for BSE calculations. "// &
    1333             :                           "Choose between full or iterative diagonalization.", &
    1334             :                           usage="BSE_DIAG_METHOD FULLDIAG", &
    1335             :                           enum_c_vals=s2a("FULLDIAG", "ITERDIAG"), &
    1336             :                           enum_i_vals=(/bse_fulldiag, bse_iterdiag/), &
    1337             :                           enum_desc=s2a("Fully diagonalizes the BSE matrices within the chosen level of approximation.", &
    1338             :                                         "Iterative diagonalization has not been implemented yet."), &
    1339       64282 :                           default_i_val=bse_fulldiag)
    1340       64282 :       CALL section_add_keyword(section, keyword)
    1341       64282 :       CALL keyword_release(keyword)
    1342             : 
    1343             :       CALL keyword_create(keyword, __LOCATION__, name="TDA", &
    1344             :                           description="Level of approximation applied to BSE calculations. "// &
    1345             :                           "Choose between Tamm Dancoff approximation (TDA) and/or diagonalization of the full ABBA-matrix.", &
    1346             :                           usage="TDA ON", &
    1347             :                           enum_c_vals=s2a("ON", "OFF", "TDA+ABBA"), &
    1348             :                           enum_i_vals=(/bse_tda, bse_abba, bse_both/), &
    1349             :                           enum_desc=s2a("The TDA is applied, i.e. B=0.", &
    1350             :                                         "The ABBA-matrix is diagonalized, i.e. the TDA is not applied.", &
    1351             :                                         "The BSE is solved within the TDA (B=0) as well as for the full ABBA-matrix."), &
    1352       64282 :                           default_i_val=bse_tda)
    1353       64282 :       CALL section_add_keyword(section, keyword)
    1354       64282 :       CALL keyword_release(keyword)
    1355             : 
    1356             :       CALL keyword_create(keyword, __LOCATION__, name="ENERGY_CUTOFF_OCC", &
    1357             :                           description="Remove all orbitals with indices i,j from A_ia,jb and B_ia,jb with energy difference "// &
    1358             :                           "to HOMO level larger than the given energy cutoff, i.e. "// &
    1359             :                "$\varepsilon_i\in[\varepsilon_{i=\text{HOMO}}^{GW}-E_\text{cut}^\text{occ},\varepsilon_{i=\text{HOMO}}^{GW}]$. "// &
    1360             :                           "Can be used to accelerate runtime and reduce memory consumption.", &
    1361             :                           usage="ENERGY_CUTOFF_OCC 10.0", unit_str="eV", &
    1362       64282 :                           type_of_var=real_t, default_r_val=-1.0_dp)
    1363       64282 :       CALL section_add_keyword(section, keyword)
    1364       64282 :       CALL keyword_release(keyword)
    1365             : 
    1366             :       CALL keyword_create(keyword, __LOCATION__, name="ENERGY_CUTOFF_EMPTY", &
    1367             :                           description="Remove all orbitals with indices a,b from A_ia,jb and B_ia,jb with energy difference "// &
    1368             :                           "to LUMO level larger than the given energy cutoff, i.e. "// &
    1369             :              "$\varepsilon_a\in[\varepsilon_{a=\text{LUMO}}^{GW},\varepsilon_{a=\text{LUMO}}^{GW}+E_\text{cut}^\text{empty}]$. "// &
    1370             :                           "Can be used to accelerate runtime and reduce memory consumption.", &
    1371             :                           usage="ENERGY_CUTOFF_EMPTY 10.0", unit_str="eV", &
    1372       64282 :                           type_of_var=real_t, default_r_val=-1.0_dp)
    1373       64282 :       CALL section_add_keyword(section, keyword)
    1374       64282 :       CALL keyword_release(keyword)
    1375             : 
    1376             :       CALL keyword_create(keyword, __LOCATION__, name="BSE_DEBUG_PRINT", &
    1377             :                           description="Activates debug print statements in the BSE calculation.", &
    1378             :                           usage="BSE_DEBUG_PRINT .TRUE.", &
    1379       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
    1380       64282 :       CALL section_add_keyword(section, keyword)
    1381       64282 :       CALL keyword_release(keyword)
    1382             : 
    1383             :       CALL keyword_create(keyword, __LOCATION__, name="NUM_PRINT_EXC", &
    1384             :                           description="Number of printed excitation levels with respective "// &
    1385             :                           "energies and oscillator strengths. Does not affect computation time.", &
    1386             :                           usage="NUM_PRINT_EXC 25", &
    1387       64282 :                           default_i_val=25)
    1388       64282 :       CALL section_add_keyword(section, keyword)
    1389       64282 :       CALL keyword_release(keyword)
    1390             : 
    1391             :       CALL keyword_create(keyword, __LOCATION__, name="NUM_PRINT_EXC_DESCR", &
    1392             :                           description="Number of excitation levels for which the exciton "// &
    1393             :                           "descriptors are computed. Negative or too large "// &
    1394             :                           "NUM_PRINT_EXC_DESCR defaults to NUM_PRINT_EXC.", &
    1395             :                           usage="NUM_PRINT_EXC_DESCR 5", &
    1396       64282 :                           default_i_val=0)
    1397       64282 :       CALL section_add_keyword(section, keyword)
    1398       64282 :       CALL keyword_release(keyword)
    1399             : 
    1400             :       CALL keyword_create(keyword, __LOCATION__, name="PRINT_DIRECTIONAL_EXC_DESCR", &
    1401             :                           description="Activates printing of exciton descriptors per direction.", &
    1402             :                           usage="PRINT_DIRECTIONAL_EXC_DESCR .TRUE.", &
    1403       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
    1404       64282 :       CALL section_add_keyword(section, keyword)
    1405       64282 :       CALL keyword_release(keyword)
    1406             : 
    1407             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_X", &
    1408             :                           description="Threshold for printing contributions of singleparticle "// &
    1409             :                           "transitions, i.e. elements of the eigenvectors $X_{ia}^{(n)}$ and $Y_{ia}^{(n)}$.", &
    1410             :                           usage="EPS_X 0.1", &
    1411       64282 :                           type_of_var=real_t, default_r_val=0.1_dp)
    1412       64282 :       CALL section_add_keyword(section, keyword)
    1413       64282 :       CALL keyword_release(keyword)
    1414             : 
    1415             :       CALL keyword_create(keyword, __LOCATION__, name="USE_KS_ENERGIES", &
    1416             :                           description="Uses KS energies instead of GW quasiparticle energies.", &
    1417             :                           usage="USE_KS_ENERGIES .TRUE.", &
    1418       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
    1419       64282 :       CALL section_add_keyword(section, keyword)
    1420       64282 :       CALL keyword_release(keyword)
    1421             : 
    1422       64282 :       NULLIFY (subsection)
    1423       64282 :       CALL create_bse_screening_section(subsection)
    1424       64282 :       CALL section_add_subsection(section, subsection)
    1425       64282 :       CALL section_release(subsection)
    1426             : 
    1427       64282 :       NULLIFY (subsection)
    1428       64282 :       CALL create_bse_iterat_section(subsection)
    1429       64282 :       CALL section_add_subsection(section, subsection)
    1430       64282 :       CALL section_release(subsection)
    1431             : 
    1432       64282 :       NULLIFY (subsection)
    1433       64282 :       CALL create_bse_spectrum_section(subsection)
    1434       64282 :       CALL section_add_subsection(section, subsection)
    1435       64282 :       CALL section_release(subsection)
    1436             : 
    1437       64282 :       NULLIFY (subsection)
    1438       64282 :       CALL create_bse_nto_section(subsection)
    1439       64282 :       CALL section_add_subsection(section, subsection)
    1440       64282 :       CALL section_release(subsection)
    1441             : 
    1442       64282 :    END SUBROUTINE
    1443             : 
    1444       64282 :    SUBROUTINE create_bse_screening_section(section)
    1445             :       TYPE(section_type), POINTER                        :: section
    1446             : 
    1447             :       TYPE(keyword_type), POINTER                        :: keyword
    1448             : 
    1449       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    1450             : 
    1451             :       CALL section_create(section, __LOCATION__, name="SCREENING_IN_W", &
    1452             :                           description="Screening $\epsilon$ applied to $W(\omega=0)=\epsilon^{-1}(\omega=0) v $ "// &
    1453             :                           "in the BSE calculation. Besides default BSE, i.e. $W_0$ (screening with DFT energies), "// &
    1454             :                           "a fixed $\alpha = \epsilon^{-1}(\omega)$ can be applied, which is similar to the mixing "// &
    1455             :                           "parameter for hybrid functionals in LR-TDDFT. In addition, the keywords TDHF "// &
    1456             :                           "(no screening - $\alpha = 1$) and RPA (infinite screening - $\alpha = 0$) can be applied.", &
    1457       64282 :                           n_keywords=2, n_subsections=0, repeats=.FALSE.)
    1458             : 
    1459       64282 :       NULLIFY (keyword)
    1460             : 
    1461             :       CALL keyword_create( &
    1462             :          keyword, __LOCATION__, name="_SECTION_PARAMETERS_", &
    1463             :          description="Shortcut for the most common functional combinations.", &
    1464             :          usage="&xc_functional BLYP", &
    1465             :          enum_c_vals=s2a("W_0", "TDHF", "RPA", "ALPHA"), &
    1466             :          enum_i_vals=(/bse_screening_w0, bse_screening_tdhf, bse_screening_rpa, bse_screening_alpha/), &
    1467             :          enum_desc=s2a("The Coulomb interaction is screened by applying DFT energies "// &
    1468             :                        "$\varepsilon_p^{DFT}$, which is typically used for GW-BSE and "// &
    1469             :                        "often labeled as $W_0$.", &
    1470             :                        "The Coulomb interaction is not screened, i.e. $W_{pq,rs}(\omega=0) "// &
    1471             :                        "\rightarrow v_{pq,rs}$ enters.", &
    1472             :                        "Infinite screening is applied, i.e. $W_{pq,rs}(\omega=0) \rightarrow 0$.", &
    1473             :                        "Arbitrary screening parameter. Specify within section."), &
    1474             :          default_i_val=bse_screening_w0, &
    1475       64282 :          lone_keyword_i_val=bse_screening_w0)
    1476       64282 :       CALL section_add_keyword(section, keyword)
    1477       64282 :       CALL keyword_release(keyword)
    1478             : 
    1479             :       CALL keyword_create(keyword, __LOCATION__, name="ALPHA", &
    1480             :                           description="Screening parameter similar to the mixing in hybrid functionals used in TDDFT. "// &
    1481             :                           "$\alpha$ mimicks the screening $\epsilon^{-1}(\omega)$ and enforces $W = \alpha v$ "// &
    1482             :                           "in the BSE calculation.", &
    1483             :                           usage="ALPHA 0.25", &
    1484       64282 :                           type_of_var=real_t, default_r_val=-1.00_dp)
    1485       64282 :       CALL section_add_keyword(section, keyword)
    1486       64282 :       CALL keyword_release(keyword)
    1487             : 
    1488       64282 :    END SUBROUTINE create_bse_screening_section
    1489             : 
    1490       64282 :    SUBROUTINE create_bse_nto_section(print_key)
    1491             :       TYPE(section_type), POINTER                        :: print_key
    1492             : 
    1493             :       TYPE(keyword_type), POINTER                        :: keyword
    1494             : 
    1495       64282 :       CPASSERT(.NOT. ASSOCIATED(print_key))
    1496             : 
    1497             :       CALL cp_print_key_section_create(print_key, __LOCATION__, name="NTO_ANALYSIS", &
    1498             :                                 description="Perform a natural transition orbital analysis, i.e. the transition density matrix "// &
    1499             :                             "$T^{(n)}=\left( \begin{array}{cc}0& {X}^{(n)}\\ \left({Y}^{(n)} \right)^T & 0\end{array} \right)$ "// &
    1500             :                                        "is decomposed into its singular values "// &
    1501             :                                        "$T^{(n)} = {U}^{(n)} {\Lambda^{(n)}} \left({V}^{(n)}\right)^T$ "// &
    1502             :                                        "in order to compute the NTO pairs "// &
    1503             :                    "$\phi_I^{(n)}(\mathbf{r}_e) = \sum_{p=1}^{N_b} \varphi_p(\mathbf{r}_e) V_{p,I}^{(n)}$ for the electron and "// &
    1504             :                             "$\chi_I^{(n)}(\mathbf{r}_h) = \sum_{q=1}^{N_b} \varphi_q(\mathbf{r}_h) U_{q,I}^{(n)}$ for the hole.", &
    1505             :                                        print_level=debug_print_level + 1, &  ! Corresponds to "off" as default behavior
    1506       64282 :                                        filename="BSE-NTO_ANALYSIS")        ! All other print levels will trigger the analysis
    1507             :       ! cf. input/cp_output_handling.F:cp_print_key_section_create
    1508             : 
    1509       64282 :       NULLIFY (keyword)
    1510             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_NTO_EIGVAL", &
    1511             :                           description="Threshold for NTO eigenvalues, i.e. only "// &
    1512             :                           "${\left(\lambda_I^{(n)}\right)}^2$ > EPS_NTO_EIGVAL are considered.", &
    1513             :                           usage="EPS_NTO_EIGVAL 0.01", &
    1514             :                           n_var=1, &
    1515             :                           type_of_var=real_t, &
    1516       64282 :                           default_r_val=0.01_dp)
    1517       64282 :       CALL section_add_keyword(print_key, keyword)
    1518       64282 :       CALL keyword_release(keyword)
    1519             : 
    1520             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_OSC_STR", &
    1521             :                           description="Threshold of oscillator strengths $f^{(n)}$ for an excitation level. "// &
    1522             :                           "In case, the excitation level n has a smaller oscillator strength, the "// &
    1523             :                           "NTOs for this excitation level are not printed.", &
    1524             :                           usage="EPS_OSC_STR 0.01", &
    1525             :                           n_var=1, &
    1526             :                           type_of_var=real_t, &
    1527       64282 :                           default_r_val=-1.0_dp)
    1528       64282 :       CALL section_add_keyword(print_key, keyword)
    1529       64282 :       CALL keyword_release(keyword)
    1530             : 
    1531             :       CALL keyword_create(keyword, __LOCATION__, name="NUM_PRINT_EXC_NTOS", &
    1532             :                           description="Number of excitation level $n$ up to which NTOs are printed. "// &
    1533             :                           "By default, this is set to NUM_PRINT_EXC. Negative or too large "// &
    1534             :                           "NUM_PRINT_EXC_NTOS defaults to NUM_PRINT_EXC.", &
    1535             :                           usage="NUM_PRINT_EXC_NTOS 5", &
    1536             :                           n_var=1, &
    1537             :                           type_of_var=integer_t, &
    1538       64282 :                           default_i_val=-1)
    1539       64282 :       CALL section_add_keyword(print_key, keyword)
    1540       64282 :       CALL keyword_release(keyword)
    1541             : 
    1542             :       CALL keyword_create(keyword, __LOCATION__, name="STATE_LIST", &
    1543             :                           description="Specifies a list of excitation levels $n$ for which NTOs are printed. "// &
    1544             :                           "Overrides NUM_PRINT_EXC_NTOS.", &
    1545             :                           usage="STATE_LIST {integer} {integer} .. {integer}", &
    1546       64282 :                           n_var=-1, type_of_var=integer_t)
    1547       64282 :       CALL section_add_keyword(print_key, keyword)
    1548       64282 :       CALL keyword_release(keyword)
    1549             : 
    1550             :       CALL keyword_create(keyword, __LOCATION__, name="CUBE_FILES", &
    1551             :                           description="Print NTOs on Cube Files", &
    1552             :                           usage="CUBE_FILES {logical}", repeats=.FALSE., n_var=1, &
    1553       64282 :                           default_l_val=.TRUE., lone_keyword_l_val=.TRUE., type_of_var=logical_t)
    1554       64282 :       CALL section_add_keyword(print_key, keyword)
    1555       64282 :       CALL keyword_release(keyword)
    1556             : 
    1557             :       CALL keyword_create(keyword, __LOCATION__, name="STRIDE", &
    1558             :                           description="The stride (X,Y,Z) used to write the cube file "// &
    1559             :                           "(larger values result in smaller cube files). Provide 3 numbers (for X,Y,Z) or"// &
    1560             :                           " 1 number valid for all components.", &
    1561       64282 :                           usage="STRIDE 2 2 2", n_var=-1, default_i_vals=(/2, 2, 2/), type_of_var=integer_t)
    1562       64282 :       CALL section_add_keyword(print_key, keyword)
    1563       64282 :       CALL keyword_release(keyword)
    1564             : 
    1565             :       CALL keyword_create(keyword, __LOCATION__, name="APPEND", &
    1566             :                           description="append the cube files when they already exist", &
    1567       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
    1568       64282 :       CALL section_add_keyword(print_key, keyword)
    1569       64282 :       CALL keyword_release(keyword)
    1570             : 
    1571       64282 :    END SUBROUTINE create_bse_nto_section
    1572             : 
    1573       64282 :    SUBROUTINE create_bse_spectrum_section(section)
    1574             :       TYPE(section_type), POINTER                        :: section
    1575             : 
    1576             :       TYPE(keyword_type), POINTER                        :: keyword
    1577             : 
    1578       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    1579             :       CALL section_create(section, __LOCATION__, name="BSE_SPECTRUM", &
    1580             :                           description="Parameters influencing the output of the optical absorption spectrum, i.e. "// &
    1581             :                           "the dynamical dipole polarizability tensor $\alpha_{\mu,\mu'}(\omega)$ "// &
    1582             :                           "($\mu,\mu'\in\{x,y,z\}$), obtained from a BSE calculation, which is defined as "// &
    1583             :                           "$ \alpha_{\mu,\mu'}(\omega) = \sum_n \frac{2 E^{(n)} d^{(n)}_{\mu} d^{(n)}_{\mu'}} "// &
    1584             :                           "{(\omega+i\eta)^2-\left(\Omega^{(n)}\right)^2} $. "// &
    1585             :                           "The printed file will contain the specified frequency range $\omega$ and the "// &
    1586             :                           "corresponding imaginary part of the average $\bar{\alpha}(\omega)=\frac{1}{3}\mathrm{Tr} "// &
    1587             :                           "\left[ \alpha_{\mu,\mu'}(\omega)\right]$ as well as of the elements of $\alpha_{\mu,\mu'}(\omega)$.", &
    1588       64282 :                           n_keywords=9, n_subsections=0, repeats=.FALSE.)
    1589             : 
    1590       64282 :       NULLIFY (keyword)
    1591             : 
    1592             :       CALL keyword_create(keyword, __LOCATION__, name="_SECTION_PARAMETERS_", &
    1593             :                           description="Activates printing of optical absorption spectrum from the BSE calculation.", &
    1594             :                           usage="&BSE .TRUE.", &
    1595       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
    1596       64282 :       CALL section_add_keyword(section, keyword)
    1597       64282 :       CALL keyword_release(keyword)
    1598             : 
    1599             :       CALL keyword_create(keyword, __LOCATION__, name="FREQUENCY_STEP_SIZE", &
    1600             :                           description="Step size of frequencies for the optical absorption spectrum.", &
    1601             :                           usage="FREQUENCY_STEP_SIZE 0.1", unit_str="eV", &
    1602             :                           type_of_var=real_t, &
    1603       64282 :                           default_r_val=cp_unit_to_cp2k(value=0.1_dp, unit_str="eV"))
    1604       64282 :       CALL section_add_keyword(section, keyword)
    1605       64282 :       CALL keyword_release(keyword)
    1606             : 
    1607             :       CALL keyword_create(keyword, __LOCATION__, name="FREQUENCY_STARTING_POINT", &
    1608             :                           description="First frequency to print in the optical absorption spectrum.", &
    1609             :                           usage="FREQUENCY_STARTING_POINT 0", unit_str="eV", &
    1610       64282 :                           type_of_var=real_t, default_r_val=0.0_dp)
    1611       64282 :       CALL section_add_keyword(section, keyword)
    1612       64282 :       CALL keyword_release(keyword)
    1613             : 
    1614             :       CALL keyword_create(keyword, __LOCATION__, name="FREQUENCY_END_POINT", &
    1615             :                           description="Last frequency to print in the optical absorption spectrum.", &
    1616             :                           usage="FREQUENCY_END_POINT 0", unit_str="eV", &
    1617             :                           type_of_var=real_t, &
    1618       64282 :                           default_r_val=cp_unit_to_cp2k(value=100.0_dp, unit_str="eV"))
    1619       64282 :       CALL section_add_keyword(section, keyword)
    1620       64282 :       CALL keyword_release(keyword)
    1621             : 
    1622             :       CALL keyword_create(keyword, __LOCATION__, name="ETA_LIST", &
    1623             :                           description="List of broadening of the peaks in the optical absorption spectrum.", &
    1624             :                           usage="ETA_LIST 0.01 ...", unit_str="eV", &
    1625             :                           default_r_vals=(/cp_unit_to_cp2k(value=0.01_dp, unit_str="eV")/), &
    1626      128564 :                           type_of_var=real_t, n_var=-1)
    1627       64282 :       CALL section_add_keyword(section, keyword)
    1628       64282 :       CALL keyword_release(keyword)
    1629             : 
    1630       64282 :    END SUBROUTINE
    1631             : 
    1632             : ! **************************************************************************************************
    1633             : !> \brief ...
    1634             : !> \param section ...
    1635             : ! **************************************************************************************************
    1636       64282 :    SUBROUTINE create_bse_iterat_section(section)
    1637             :       TYPE(section_type), POINTER                        :: section
    1638             : 
    1639             :       TYPE(keyword_type), POINTER                        :: keyword
    1640             : 
    1641       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    1642             :       CALL section_create(section, __LOCATION__, name="BSE_ITERAT", &
    1643             :                           description="Parameters influencing the iterative Bethe-Salpeter calculation. "// &
    1644             :                           "The iterative solver has not been fully implemented yet.", &
    1645       64282 :                           n_keywords=9, n_subsections=0, repeats=.FALSE.)
    1646             : 
    1647       64282 :       NULLIFY (keyword)
    1648             : 
    1649             :       CALL keyword_create(keyword, __LOCATION__, name="DAVIDSON_ABORT_COND", &
    1650             :                           description="Desired abortion condition for Davidson solver", &
    1651             :                           usage="DAVIDSON_ABORT_COND OR", &
    1652             :                           enum_c_vals=s2a("EN", "RES", "OR"), &
    1653             :                           enum_i_vals=(/bse_iter_en_cond, bse_iter_res_cond, bse_iter_both_cond/), &
    1654             :                           enum_desc=s2a("Uses energy threshold for successfully exiting solver.", &
    1655             :                                         "Uses residual threshold for successfully exiting solver.", &
    1656             :                                         "Uses either energy or residual threshold for successfully exiting solver."), &
    1657       64282 :                           default_i_val=bse_iter_en_cond)
    1658       64282 :       CALL section_add_keyword(section, keyword)
    1659       64282 :       CALL keyword_release(keyword)
    1660             : 
    1661             :       CALL keyword_create(keyword, __LOCATION__, name="NUM_EXC_EN", &
    1662             :                           description="Number of lowest excitation energies to be computed.", &
    1663             :                           usage="NUM_EXC_EN 3", &
    1664       64282 :                           default_i_val=3)
    1665       64282 :       CALL section_add_keyword(section, keyword)
    1666       64282 :       CALL keyword_release(keyword)
    1667             : 
    1668             :       CALL keyword_create(keyword, __LOCATION__, name="NUM_ADD_START_Z_SPACE", &
    1669             :                           description="Determines the initial dimension of the subspace as "// &
    1670             :                           "dim = (NUM_EXC_EN+NUM_ADD_START_Z_SPACE)", &
    1671             :                           usage="NUM_ADD_START_Z_SPACE 1", &
    1672       64282 :                           default_i_val=0)
    1673       64282 :       CALL section_add_keyword(section, keyword)
    1674       64282 :       CALL keyword_release(keyword)
    1675             : 
    1676             :       CALL keyword_create(keyword, __LOCATION__, name="FAC_MAX_Z_SPACE", &
    1677             :                           description="Factor to determine maximum dimension of the Davidson subspace. "// &
    1678             :                           "dimension = (NUM_EXC_EN+NUM_ADD_START_Z_SPACE)*FAC_MAX_Z_SPACE", &
    1679             :                           usage="FAC_MAX_Z_SPACE 5", &
    1680       64282 :                           default_i_val=5)
    1681       64282 :       CALL section_add_keyword(section, keyword)
    1682       64282 :       CALL keyword_release(keyword)
    1683             : 
    1684             :       CALL keyword_create(keyword, __LOCATION__, name="NUM_NEW_T", &
    1685             :                           description="Number of new t vectors added. "// &
    1686             :                           "Must be smaller/equals (NUM_EXC_EN+NUM_ADD_START_Z_SPACE)", &
    1687             :                           usage="NUM_NEW_T 4", &
    1688       64282 :                           default_i_val=1)
    1689       64282 :       CALL section_add_keyword(section, keyword)
    1690       64282 :       CALL keyword_release(keyword)
    1691             : 
    1692             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_RES", &
    1693             :                           description="Threshold for stopping the iteration for computing the transition energies. "// &
    1694             :                           "If the residuals inside the Davidson space change by less than EPS_RES (in eV), the iteration "// &
    1695             :                           "stops.", &
    1696             :                           usage="EPS_RES 0.001", unit_str="eV", &
    1697       64282 :                           type_of_var=real_t, default_r_val=0.001_dp)
    1698       64282 :       CALL section_add_keyword(section, keyword)
    1699       64282 :       CALL keyword_release(keyword)
    1700             : 
    1701             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_EXC_EN", &
    1702             :                           description="Threshold for stopping the iteration for computing the transition energies. "// &
    1703             :                           "If the desired excitation energies change by less than EPS_EXC_EN (in eV), the iteration "// &
    1704             :                           "stops.", &
    1705             :                           usage="EPS_EXC_EN 0.001", unit_str="eV", &
    1706       64282 :                           type_of_var=real_t, default_r_val=0.001_dp)
    1707       64282 :       CALL section_add_keyword(section, keyword)
    1708       64282 :       CALL keyword_release(keyword)
    1709             : 
    1710             :       CALL keyword_create(keyword, __LOCATION__, name="NUM_DAVIDSON_ITER", &
    1711             :                           description="Maximum number of iterations for determining the transition energies.", &
    1712             :                           usage="MAX_ITER 100", &
    1713       64282 :                           default_i_val=100)
    1714       64282 :       CALL section_add_keyword(section, keyword)
    1715       64282 :       CALL keyword_release(keyword)
    1716             : 
    1717             :       CALL keyword_create(keyword, __LOCATION__, name="Z_SPACE_ENERGY_CUTOFF", &
    1718             :                           description="Cutoff (in eV) for maximal energy difference entering the A matrix. "// &
    1719             :                           "Per default and for negative values, there is no cutoff applied.", &
    1720             :                           usage="Z_SPACE_ENERGY_CUTOFF 60", unit_str="eV", &
    1721       64282 :                           type_of_var=real_t, default_r_val=-1.0_dp)
    1722       64282 :       CALL section_add_keyword(section, keyword)
    1723       64282 :       CALL keyword_release(keyword)
    1724       64282 :    END SUBROUTINE
    1725             : 
    1726             : ! **************************************************************************************************
    1727             : !> \brief ...
    1728             : !> \param section ...
    1729             : ! **************************************************************************************************
    1730       64282 :    SUBROUTINE create_ic_section(section)
    1731             :       TYPE(section_type), POINTER                        :: section
    1732             : 
    1733             :       TYPE(keyword_type), POINTER                        :: keyword
    1734             : 
    1735       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    1736             :       CALL section_create(section, __LOCATION__, name="IC", &
    1737             :                           description="Parameters influencing the image charge correction. "// &
    1738             :                           "The image plane is always an xy plane, so adjust the molecule according "// &
    1739             :                           "to that. ", &
    1740       64282 :                           n_keywords=3, n_subsections=1, repeats=.FALSE.)
    1741             : 
    1742       64282 :       NULLIFY (keyword)
    1743             : 
    1744             :       CALL keyword_create(keyword, __LOCATION__, name="PRINT_IC_LIST", &
    1745             :                           description="If true, the image charge correction values are printed in a list, "// &
    1746             :                           "such that it can be used as input for a subsequent evGW calculation.", &
    1747             :                           usage="PRINT_IC_VALUES", &
    1748             :                           default_l_val=.FALSE., &
    1749       64282 :                           lone_keyword_l_val=.TRUE.)
    1750       64282 :       CALL section_add_keyword(section, keyword)
    1751       64282 :       CALL keyword_release(keyword)
    1752             : 
    1753             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_DIST", &
    1754             :                           description="Threshold where molecule and image molecule have to coincide. ", &
    1755             :                           usage="EPS_DIST 0.1", unit_str="angstrom", &
    1756       64282 :                           type_of_var=real_t, default_r_val=3.0E-02_dp, repeats=.FALSE.)
    1757       64282 :       CALL section_add_keyword(section, keyword)
    1758       64282 :       CALL keyword_release(keyword)
    1759             : 
    1760       64282 :    END SUBROUTINE
    1761             : 
    1762             : ! **************************************************************************************************
    1763             : !> \brief ...
    1764             : !> \param section ...
    1765             : ! **************************************************************************************************
    1766       64282 :    SUBROUTINE create_low_scaling(section)
    1767             :       TYPE(section_type), POINTER                        :: section
    1768             : 
    1769             :       TYPE(keyword_type), POINTER                        :: keyword
    1770             :       TYPE(section_type), POINTER                        :: subsection
    1771             : 
    1772       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    1773             :       CALL section_create( &
    1774             :          section, __LOCATION__, name="LOW_SCALING", &
    1775             :          description="Cubic scaling RI-RPA, GW and Laplace-SOS-MP2 method using the imaginary time formalism. "// &
    1776             :          "EPS_GRID in WFC_GPW section controls accuracy / req. memory for 3-center integrals. "// &
    1777             :          "SORT_BASIS EXP should be specified in DFT section.", &
    1778             :          n_keywords=12, n_subsections=2, repeats=.FALSE., &
    1779      257128 :          citations=(/Wilhelm2016b, Wilhelm2018, Bussy2023/))
    1780             : 
    1781       64282 :       NULLIFY (keyword)
    1782             :       CALL keyword_create(keyword, __LOCATION__, name="_SECTION_PARAMETERS_", &
    1783             :                           description="Activates cubic-scaling RPA, GW and Laplace-SOS-MP2 calculations.", &
    1784             :                           usage="&LOW_SCALING .TRUE.", &
    1785       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
    1786       64282 :       CALL section_add_keyword(section, keyword)
    1787       64282 :       CALL keyword_release(keyword)
    1788             : 
    1789             :       CALL keyword_create(keyword, __LOCATION__, name="MEMORY_CUT", &
    1790             :                           description="Reduces memory for sparse tensor contractions by this factor. "// &
    1791             :                           "A high value leads to some loss of performance. "// &
    1792             :                           "This memory reduction factor applies to storage of the tensors 'M occ' / 'M virt' "// &
    1793             :                           "but does not reduce storage of '3c ints'.", &
    1794             :                           usage="MEMORY_CUT 16", &
    1795       64282 :                           default_i_val=5)
    1796       64282 :       CALL section_add_keyword(section, keyword)
    1797       64282 :       CALL keyword_release(keyword)
    1798             : 
    1799             :       CALL keyword_create(keyword, __LOCATION__, name="MEMORY_INFO", &
    1800             :                           description="Decide whether to print memory info on the sparse matrices.", &
    1801             :                           usage="MEMORY_INFO", &
    1802             :                           default_l_val=.FALSE., &
    1803       64282 :                           lone_keyword_l_val=.TRUE.)
    1804       64282 :       CALL section_add_keyword(section, keyword)
    1805       64282 :       CALL keyword_release(keyword)
    1806             : 
    1807             :       CALL keyword_create( &
    1808             :          keyword, __LOCATION__, name="EPS_FILTER", &
    1809             :          description="Determines a threshold for the DBCSR based multiply. "// &
    1810             :          "Normally, this EPS_FILTER determines accuracy and timing of low-scaling RPA and GW calculations.", &
    1811             :          usage="EPS_FILTER 1.0E-10 ", type_of_var=real_t, &
    1812       64282 :          default_r_val=1.0E-9_dp)
    1813       64282 :       CALL section_add_keyword(section, keyword)
    1814       64282 :       CALL keyword_release(keyword)
    1815             : 
    1816             :       CALL keyword_create( &
    1817             :          keyword, __LOCATION__, name="EPS_FILTER_FACTOR", &
    1818             :          description="Multiply EPS_FILTER with this factor to determine filter epsilon "// &
    1819             :          "for DBCSR based multiply P(it)=(Mocc(it))^T*Mvirt(it) "// &
    1820             :          "Default should be kept.", &
    1821             :          type_of_var=real_t, &
    1822       64282 :          default_r_val=10.0_dp)
    1823       64282 :       CALL section_add_keyword(section, keyword)
    1824       64282 :       CALL keyword_release(keyword)
    1825             : 
    1826             :       CALL keyword_create( &
    1827             :          keyword, __LOCATION__, &
    1828             :          name="EPS_STORAGE_SCALING", &
    1829             :          variants=(/"EPS_STORAGE"/), &
    1830             :          description="Scaling factor to scale EPS_FILTER. Storage threshold for compression "// &
    1831             :          "will be EPS_FILTER*EPS_STORAGE_SCALING.", &
    1832      128564 :          default_r_val=1.0E-3_dp)
    1833       64282 :       CALL section_add_keyword(section, keyword)
    1834       64282 :       CALL keyword_release(keyword)
    1835             : 
    1836             :       CALL keyword_create( &
    1837             :          keyword, __LOCATION__, &
    1838             :          name="DO_KPOINTS", &
    1839             :          description="Besides in DFT, this keyword has to be switched on if one wants to do kpoints in. "// &
    1840             :          "cubic RPA.", &
    1841             :          usage="DO_KPOINTS", &
    1842             :          default_l_val=.FALSE., &
    1843       64282 :          lone_keyword_l_val=.TRUE.)
    1844       64282 :       CALL section_add_keyword(section, keyword)
    1845       64282 :       CALL keyword_release(keyword)
    1846             : 
    1847             :       CALL keyword_create( &
    1848             :          keyword, __LOCATION__, name="KPOINTS", &
    1849             :          description="Keyword activates periodic, low-scaling GW calculations (&LOW_SCALING section also needed). "// &
    1850             :          "For periodic calculations, kpoints are used for the density response, the "// &
    1851             :          "Coulomb interaction and the screened Coulomb interaction. For 2d periodic systems, e.g. xz "// &
    1852             :          "periodicity, please also specify KPOINTS, e.g.  N_x  1  N_z.", &
    1853             :          usage="KPOINTS  N_x  N_y  N_z", &
    1854       64282 :          n_var=3, type_of_var=integer_t, default_i_vals=(/0, 0, 0/))
    1855       64282 :       CALL section_add_keyword(section, keyword)
    1856       64282 :       CALL keyword_release(keyword)
    1857             : 
    1858             :       CALL keyword_create( &
    1859             :          keyword, __LOCATION__, &
    1860             :          name="KPOINT_WEIGHTS_W", &
    1861             :          description="For kpoints in low-scaling GW, a Monkhorst-Pack mesh is used. The screened Coulomb "// &
    1862             :          "interaction W(k) needs special care near the Gamma point (e.g. in 3d, W(k) diverges at the "// &
    1863             :          "Gamma point with W(k) ~ k^alpha). KPOINT_WEIGHTS_W decides how the weights of the "// &
    1864             :          "Monkhorst-Pack mesh are chosen to compute W(R) = int_BZ W(k) exp(ikR) dk (BZ=Brllouin zone). ", &
    1865             :          usage="KPOINT_WEIGHTS_W AUTO", &
    1866             :          enum_c_vals=s2a("TAILORED", "AUTO", "UNIFORM"), &
    1867             :          enum_i_vals=(/kp_weights_W_tailored, kp_weights_W_auto, kp_weights_W_uniform/), &
    1868             :          enum_desc=s2a("Choose k-point integration weights such that the function f(k)=k^alpha is "// &
    1869             :                        "exactly integrated. alpha is specified using EXPONENT_TAILORED_WEIGHTS.", &
    1870             :                        "As 'TAILORED', but alpha is chosen automatically according to dimensionality "// &
    1871             :                        "(3D: alpha = -2 for 3D, 2D: alpha = -1 for exchange self-energy, uniform "// &
    1872             :                        "weights for correlation self-energy).", &
    1873             :                        "Choose the same weight for every k-point (original Monkhorst-Pack method)."), &
    1874       64282 :          default_i_val=kp_weights_W_uniform)
    1875       64282 :       CALL section_add_keyword(section, keyword)
    1876       64282 :       CALL keyword_release(keyword)
    1877             : 
    1878             :       CALL keyword_create( &
    1879             :          keyword, __LOCATION__, &
    1880             :          name="EXPONENT_TAILORED_WEIGHTS", &
    1881             :          description="Gives the exponent of exactly integrated function in case 'KPOINT_WEIGHTS_W "// &
    1882             :          "TAILORED' is chosen.", &
    1883             :          usage="EXPONENT_TAILORED_WEIGHTS -2", &
    1884       64282 :          default_r_val=-2.0_dp)
    1885       64282 :       CALL section_add_keyword(section, keyword)
    1886       64282 :       CALL keyword_release(keyword)
    1887             : 
    1888             :       CALL keyword_create( &
    1889             :          keyword, __LOCATION__, &
    1890             :          name="REGULARIZATION_RI", &
    1891             :          description="Parameter to reduce the expansion coefficients in RI for periodic GW. Larger parameter "// &
    1892             :          "means smaller expansion coefficients that leads to a more stable calculation at the price "// &
    1893             :          "of a slightly worse RI approximation. In case the parameter 0.0 is chosen, ordinary RI is used.", &
    1894             :          usage="REGULARIZATION_RI 1.0E-4", &
    1895       64282 :          default_r_val=0.0_dp)
    1896       64282 :       CALL section_add_keyword(section, keyword)
    1897       64282 :       CALL keyword_release(keyword)
    1898             : 
    1899             :       CALL keyword_create( &
    1900             :          keyword, __LOCATION__, &
    1901             :          name="EPS_EIGVAL_S", &
    1902             :          description="Parameter to reduce the expansion coefficients in RI for periodic GW. Removes all "// &
    1903             :          "eigenvectors and eigenvalues of S_PQ(k) that are smaller than EPS_EIGVAL_S. ", &
    1904             :          usage="EPS_EIGVAL_S 1.0E-3", &
    1905       64282 :          default_r_val=0.0_dp)
    1906       64282 :       CALL section_add_keyword(section, keyword)
    1907       64282 :       CALL keyword_release(keyword)
    1908             : 
    1909             :       CALL keyword_create( &
    1910             :          keyword, __LOCATION__, &
    1911             :          name="EPS_EIGVAL_S_GAMMA", &
    1912             :          description="Parameter to reduce the expansion coefficients in RI for periodic GW. Removes all "// &
    1913             :          "eigenvectors and eigenvalues of M_PQ(k=0) that are smaller than EPS_EIGVAL_S. ", &
    1914             :          usage="EPS_EIGVAL_S 1.0E-3", &
    1915       64282 :          default_r_val=0.0_dp)
    1916       64282 :       CALL section_add_keyword(section, keyword)
    1917       64282 :       CALL keyword_release(keyword)
    1918             : 
    1919             :       CALL keyword_create( &
    1920             :          keyword, __LOCATION__, &
    1921             :          name="MAKE_CHI_POS_DEFINITE", &
    1922             :          description="If true, makes eigenvalue decomposition of chi(iw,k) and removes negative "// &
    1923             :          "eigenvalues. May increase computational cost significantly. Only recommended to try in case "// &
    1924             :          "Cholesky decomposition of epsilon(iw,k) fails.", &
    1925             :          usage="MAKE_CHI_POS_DEFINITE", &
    1926             :          default_l_val=.TRUE., &
    1927       64282 :          lone_keyword_l_val=.TRUE.)
    1928       64282 :       CALL section_add_keyword(section, keyword)
    1929       64282 :       CALL keyword_release(keyword)
    1930             : 
    1931             :       CALL keyword_create( &
    1932             :          keyword, __LOCATION__, &
    1933             :          name="MAKE_OVERLAP_MAT_AO_POS_DEFINITE", &
    1934             :          description="If true, makes eigenvalue decomposition of S_mu,nu(k) and removes negative "// &
    1935             :          "eigenvalues. Slightly increases computational cost. Only recommended to try in case "// &
    1936             :          "Cholesky decomposition of S_mu,nu(k) fails (error message: Cholesky decompose failed: "// &
    1937             :          "matrix is not positive definite or ill-conditioned; when calling create_kp_and_calc_kp_orbitals).", &
    1938             :          usage="MAKE_OVERLAP_MAT_AO_POS_DEFINITE", &
    1939             :          default_l_val=.FALSE., &
    1940       64282 :          lone_keyword_l_val=.TRUE.)
    1941       64282 :       CALL section_add_keyword(section, keyword)
    1942       64282 :       CALL keyword_release(keyword)
    1943             : 
    1944             :       CALL keyword_create( &
    1945             :          keyword, __LOCATION__, &
    1946             :          name="DO_EXTRAPOLATE_KPOINTS", &
    1947             :          description="If true, use a larger k-mesh to extrapolate the k-point integration of W. "// &
    1948             :          "For example, in 2D, when using  KPOINTS 4 4 1, an additional 6x6x1 mesh will be used to "// &
    1949             :          "extrapolate the k-point integration of W with N_k^-0.5, where Nk is the number of k-points.", &
    1950             :          usage="DO_EXTRAPOLATE_KPOINTS FALSE", &
    1951             :          default_l_val=.TRUE., &
    1952       64282 :          lone_keyword_l_val=.TRUE.)
    1953       64282 :       CALL section_add_keyword(section, keyword)
    1954       64282 :       CALL keyword_release(keyword)
    1955             : 
    1956             :       CALL keyword_create( &
    1957             :          keyword, __LOCATION__, &
    1958             :          name="TRUNC_COULOMB_RI_X", &
    1959             :          description="If true, use the truncated Coulomb operator for the exchange-self-energy in "// &
    1960             :          "periodic GW.", &
    1961             :          usage="TRUNC_COULOMB_RI_X", &
    1962             :          default_l_val=.TRUE., &
    1963       64282 :          lone_keyword_l_val=.TRUE.)
    1964       64282 :       CALL section_add_keyword(section, keyword)
    1965       64282 :       CALL keyword_release(keyword)
    1966             : 
    1967             :       CALL keyword_create( &
    1968             :          keyword, __LOCATION__, &
    1969             :          name="REL_CUTOFF_TRUNC_COULOMB_RI_X", &
    1970             :          description="Only active in case TRUNC_COULOMB_RI_X = True. Normally, relative cutoff = 0.5 is "// &
    1971             :          "good choice; still needs to be evaluated for RI schemes. ", &
    1972             :          usage="REL_CUTOFF_TRUNC_COULOMB_RI_X 0.3", &
    1973       64282 :          default_r_val=0.5_dp)
    1974       64282 :       CALL section_add_keyword(section, keyword)
    1975       64282 :       CALL keyword_release(keyword)
    1976             : 
    1977             :       CALL keyword_create( &
    1978             :          keyword, __LOCATION__, &
    1979             :          name="KEEP_QUADRATURE", &
    1980             :          variants=s2a("KEEP_WEIGHTS", "KEEP_QUAD", "KEEP_WEIGHT"), &
    1981             :          description="Keep the Laplace quadrature defined at the first energy evaluations throughout "// &
    1982             :          "the run. Allows to have consistent force evaluations.", &
    1983             :          usage="KEEP_QUADRATURE", &
    1984             :          default_l_val=.TRUE., &
    1985       64282 :          lone_keyword_l_val=.TRUE.)
    1986       64282 :       CALL section_add_keyword(section, keyword)
    1987       64282 :       CALL keyword_release(keyword)
    1988             : 
    1989             :       CALL keyword_create( &
    1990             :          keyword, __LOCATION__, &
    1991             :          name="K_MESH_G_FACTOR", &
    1992             :          description="The k-mesh for the Green's function can be chosen to be larger than the k-mesh for "// &
    1993             :          "W (without much higher computational cost). The factor given here multiplies the mesh for W to obtain "// &
    1994             :          "the k-mesh for G. Example: factor 4, k-mesh for W: 4x4x1 -> k-mesh for G: 16x16x1 (z-dir. is "// &
    1995             :          "non-periodic).", &
    1996       64282 :          default_i_val=1)
    1997       64282 :       CALL section_add_keyword(section, keyword)
    1998       64282 :       CALL keyword_release(keyword)
    1999             : 
    2000             :       CALL keyword_create( &
    2001             :          keyword, __LOCATION__, &
    2002             :          name="MIN_BLOCK_SIZE", &
    2003             :          description="Minimum tensor block size. Adjusting this value may have minor effect on "// &
    2004             :          "performance but default should be good enough.", &
    2005       64282 :          default_i_val=5)
    2006       64282 :       CALL section_add_keyword(section, keyword)
    2007       64282 :       CALL keyword_release(keyword)
    2008             : 
    2009             :       CALL keyword_create( &
    2010             :          keyword, __LOCATION__, &
    2011             :          name="MIN_BLOCK_SIZE_MO", &
    2012             :          description="Tensor block size for MOs. Only relevant for GW calculations. "// &
    2013             :          "The memory consumption of GW scales as O(MIN_BLOCK_SIZE_MO). It is recommended to "// &
    2014             :          "set this parameter to a smaller number if GW runs out of memory. "// &
    2015             :          "Otherwise the default should not be changed.", &
    2016       64282 :          default_i_val=64)
    2017       64282 :       CALL section_add_keyword(section, keyword)
    2018       64282 :       CALL keyword_release(keyword)
    2019             : 
    2020       64282 :       NULLIFY (subsection)
    2021       64282 :       CALL create_low_scaling_cphf(subsection)
    2022       64282 :       CALL section_add_subsection(section, subsection)
    2023       64282 :       CALL section_release(subsection)
    2024             : 
    2025       64282 :    END SUBROUTINE
    2026             : 
    2027             : ! **************************************************************************************************
    2028             : !> \brief ...
    2029             : !> \param section ...
    2030             : ! **************************************************************************************************
    2031       64282 :    SUBROUTINE create_wfc_gpw(section)
    2032             :       TYPE(section_type), POINTER                        :: section
    2033             : 
    2034             :       TYPE(keyword_type), POINTER                        :: keyword
    2035             : 
    2036       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    2037             :       CALL section_create(section, __LOCATION__, name="WFC_GPW", &
    2038             :                           description="Parameters for the GPW approach in Wavefunction-based Correlation methods", &
    2039       64282 :                           n_keywords=5, n_subsections=0, repeats=.FALSE.)
    2040             : 
    2041       64282 :       NULLIFY (keyword)
    2042             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_GRID", &
    2043             :                           description="Determines a threshold for the GPW based integration", &
    2044             :                           usage="EPS_GRID 1.0E-9 ", type_of_var=real_t, &
    2045       64282 :                           default_r_val=1.0E-8_dp)
    2046       64282 :       CALL section_add_keyword(section, keyword)
    2047       64282 :       CALL keyword_release(keyword)
    2048             : 
    2049             :       CALL keyword_create( &
    2050             :          keyword, __LOCATION__, name="EPS_FILTER", &
    2051             :          description="Determines a threshold for the DBCSR based multiply (usually 10 times smaller than EPS_GRID). "// &
    2052             :          "Normally, this EPS_FILTER determines accuracy and timing of cubic-scaling RPA calculation.", &
    2053             :          usage="EPS_FILTER 1.0E-10 ", type_of_var=real_t, &
    2054       64282 :          default_r_val=1.0E-9_dp)
    2055       64282 :       CALL section_add_keyword(section, keyword)
    2056       64282 :       CALL keyword_release(keyword)
    2057             : 
    2058             :       CALL keyword_create(keyword, __LOCATION__, name="CUTOFF", &
    2059             :                           description="The cutoff of the finest grid level in the MP2 gpw integration.", &
    2060             :                           usage="CUTOFF 300", type_of_var=real_t, &
    2061       64282 :                           default_r_val=300.0_dp)
    2062       64282 :       CALL section_add_keyword(section, keyword)
    2063       64282 :       CALL keyword_release(keyword)
    2064             : 
    2065             :       CALL keyword_create(keyword, __LOCATION__, name="REL_CUTOFF", &
    2066             :                           variants=(/"RELATIVE_CUTOFF"/), &
    2067             :                           description="Determines the grid at which a Gaussian is mapped.", &
    2068             :                           usage="REL_CUTOFF 50", type_of_var=real_t, &
    2069      128564 :                           default_r_val=50.0_dp)
    2070       64282 :       CALL section_add_keyword(section, keyword)
    2071       64282 :       CALL keyword_release(keyword)
    2072             : 
    2073             :       CALL keyword_create(keyword, __LOCATION__, name="PRINT_LEVEL", &
    2074             :                           variants=(/"IOLEVEL"/), &
    2075             :                           description="How much output is written by the individual groups.", &
    2076             :                           usage="PRINT_LEVEL HIGH", &
    2077             :                           default_i_val=silent_print_level, enum_c_vals= &
    2078             :                           s2a("SILENT", "LOW", "MEDIUM", "HIGH", "DEBUG"), &
    2079             :                           enum_desc=s2a("Almost no output", &
    2080             :                                         "Little output", "Quite some output", "Lots of output", &
    2081             :                                         "Everything is written out, useful for debugging purposes only"), &
    2082             :                           enum_i_vals=(/silent_print_level, low_print_level, medium_print_level, &
    2083      128564 :                                         high_print_level, debug_print_level/))
    2084       64282 :       CALL section_add_keyword(section, keyword)
    2085       64282 :       CALL keyword_release(keyword)
    2086             : 
    2087             :       CALL keyword_create( &
    2088             :          keyword, __LOCATION__, name="EPS_PGF_ORB_S", &
    2089             :          description="Screening for overlap matrix in RI. Usually, it is best to choose this parameter "// &
    2090             :          "to be very small since the inversion of overlap matrix might be ill-conditioned.", &
    2091             :          usage="EPS_PGF_ORB_S 1.0E-10 ", type_of_var=real_t, &
    2092       64282 :          default_r_val=1.0E-10_dp)
    2093       64282 :       CALL section_add_keyword(section, keyword)
    2094       64282 :       CALL keyword_release(keyword)
    2095             : 
    2096       64282 :    END SUBROUTINE create_wfc_gpw
    2097             : 
    2098             : ! **************************************************************************************************
    2099             : !> \brief ...
    2100             : !> \param section ...
    2101             : ! **************************************************************************************************
    2102       64282 :    SUBROUTINE create_cphf(section)
    2103             :       TYPE(section_type), POINTER                        :: section
    2104             : 
    2105             :       TYPE(keyword_type), POINTER                        :: keyword
    2106             : 
    2107       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    2108             :       CALL section_create( &
    2109             :          section, __LOCATION__, name="CPHF", &
    2110             :          description="Parameters influencing the solution of the Z-vector equations in MP2 gradients calculations.", &
    2111             :          n_keywords=2, n_subsections=0, repeats=.FALSE., &
    2112      128564 :          citations=(/DelBen2013/))
    2113             : 
    2114       64282 :       NULLIFY (keyword)
    2115             : 
    2116             :       CALL keyword_create(keyword, __LOCATION__, name="MAX_ITER", &
    2117             :                           variants=(/"MAX_NUM_ITER"/), &
    2118             :                           description="Maximum number of iterations allowed for the solution of the Z-vector equations.", &
    2119             :                           usage="MAX_ITER  50", &
    2120      128564 :                           default_i_val=30)
    2121       64282 :       CALL section_add_keyword(section, keyword)
    2122       64282 :       CALL keyword_release(keyword)
    2123             : 
    2124             :       CALL keyword_create(keyword, __LOCATION__, name="RESTART_EVERY", &
    2125             :                           description="Restart iteration every given number of steps.", &
    2126             :                           usage="RESTART_EVERY 5", &
    2127       64282 :                           default_i_val=5)
    2128       64282 :       CALL section_add_keyword(section, keyword)
    2129       64282 :       CALL keyword_release(keyword)
    2130             : 
    2131             :       CALL keyword_create(keyword, __LOCATION__, name="SOLVER_METHOD", &
    2132             :                           description="Chose solver of the z-vector equations.", &
    2133             :                           usage="SOLVER_METHOD POPLE", enum_c_vals= &
    2134             :                           s2a("POPLE", "CG", "RICHARDSON", "SD"), &
    2135             :                           enum_desc=s2a("Pople's method (Default).", &
    2136             :                                         "Conjugated gradient method (equivalent to Pople).", &
    2137             :                                         "Richardson iteration", &
    2138             :                                         "Steepest Descent iteration"), &
    2139             :                           enum_i_vals=(/z_solver_pople, z_solver_cg, z_solver_richardson, z_solver_sd/), &
    2140       64282 :                           default_i_val=z_solver_pople)
    2141       64282 :       CALL section_add_keyword(section, keyword)
    2142       64282 :       CALL keyword_release(keyword)
    2143             : 
    2144             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_CONV", &
    2145             :                           description="Convergence threshold for the solution of the Z-vector equations. "// &
    2146             :                           "The Z-vector equations have the form of a linear system of equations Ax=b, "// &
    2147             :                           "convergence is achieved when |Ax-b|<=EPS_CONV.", &
    2148             :                           usage="EPS_CONV 1.0E-6", type_of_var=real_t, &
    2149       64282 :                           default_r_val=1.0E-4_dp)
    2150       64282 :       CALL section_add_keyword(section, keyword)
    2151       64282 :       CALL keyword_release(keyword)
    2152             : 
    2153             :       CALL keyword_create(keyword, __LOCATION__, name="SCALE_STEP_SIZE", &
    2154             :                           description="Scaling factor of each step.", &
    2155             :                           usage="SCALE_STEP_SIZE 1.0", &
    2156       64282 :                           default_r_val=1.0_dp)
    2157       64282 :       CALL section_add_keyword(section, keyword)
    2158       64282 :       CALL keyword_release(keyword)
    2159             : 
    2160             :       CALL keyword_create(keyword, __LOCATION__, name="ENFORCE_DECREASE", &
    2161             :                           description="Restarts if residual does not decrease.", &
    2162             :                           usage="ENFORCE_DECREASE T", &
    2163             :                           lone_keyword_l_val=.TRUE., &
    2164       64282 :                           default_l_val=.FALSE.)
    2165       64282 :       CALL section_add_keyword(section, keyword)
    2166       64282 :       CALL keyword_release(keyword)
    2167             : 
    2168             :       CALL keyword_create(keyword, __LOCATION__, name="DO_POLAK_RIBIERE", &
    2169             :                           description="Use a Polak-Ribiere update of the search vector in CG instead of the Fletcher "// &
    2170             :                           "Reeves update. Improves the convergence with modified step sizes. "// &
    2171             :                           "Ignored with other methods than CG.", &
    2172             :                           usage="ENFORCE_DECREASE T", &
    2173             :                           lone_keyword_l_val=.TRUE., &
    2174       64282 :                           default_l_val=.FALSE.)
    2175       64282 :       CALL section_add_keyword(section, keyword)
    2176       64282 :       CALL keyword_release(keyword)
    2177             : 
    2178             :       CALL keyword_create(keyword, __LOCATION__, name="RECALC_RESIDUAL", &
    2179             :                           description="Recalculates residual in every step.", &
    2180             :                           usage="RECALC_RESIDUAL T", &
    2181             :                           lone_keyword_l_val=.TRUE., &
    2182       64282 :                           default_l_val=.FALSE.)
    2183       64282 :       CALL section_add_keyword(section, keyword)
    2184       64282 :       CALL keyword_release(keyword)
    2185             : 
    2186       64282 :    END SUBROUTINE create_cphf
    2187             : 
    2188             : ! **************************************************************************************************
    2189             : !> \brief ...
    2190             : !> \param section ...
    2191             : ! **************************************************************************************************
    2192       64282 :    SUBROUTINE create_low_scaling_cphf(section)
    2193             :       TYPE(section_type), POINTER                        :: section
    2194             : 
    2195             :       TYPE(keyword_type), POINTER                        :: keyword
    2196             : 
    2197       64282 :       NULLIFY (keyword)
    2198             : 
    2199       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    2200             :       CALL section_create(section, __LOCATION__, name="CPHF", &
    2201             :                           description="Parameters influencing the solution of the Z-vector equations "// &
    2202             :                           "in low-scaling Laplace-SOS-MP2 gradients calculations.", &
    2203       64282 :                           n_keywords=5, n_subsections=0, repeats=.FALSE.)
    2204             : 
    2205             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_CONV", &
    2206             :                           description="Target accuracy for Z-vector euation solution.", &
    2207       64282 :                           usage="EPS 1.e-6", default_r_val=1.e-6_dp)
    2208       64282 :       CALL section_add_keyword(section, keyword)
    2209       64282 :       CALL keyword_release(keyword)
    2210             : 
    2211             :       CALL keyword_create(keyword, __LOCATION__, name="MAX_ITER", &
    2212             :                           description="Maximum number of conjugate gradient iteration to be performed for one optimization.", &
    2213       64282 :                           usage="MAX_ITER 200", default_i_val=50)
    2214       64282 :       CALL section_add_keyword(section, keyword)
    2215       64282 :       CALL keyword_release(keyword)
    2216             : 
    2217             :       CALL keyword_create( &
    2218             :          keyword, __LOCATION__, name="PRECONDITIONER", &
    2219             :          description="Type of preconditioner to be used with all minimization schemes. "// &
    2220             :          "They differ in effectiveness, cost of construction, cost of application. "// &
    2221             :          "Properly preconditioned minimization can be orders of magnitude faster than doing nothing.", &
    2222             :          usage="PRECONDITIONER FULL_ALL", &
    2223             :          default_i_val=ot_precond_full_all, &
    2224             :          enum_c_vals=s2a("FULL_ALL", "FULL_SINGLE_INVERSE", "FULL_SINGLE", "FULL_KINETIC", "FULL_S_INVERSE", &
    2225             :                          "NONE"), &
    2226             :          enum_desc=s2a("Most effective state selective preconditioner based on diagonalization, "// &
    2227             :                        "requires the ENERGY_GAP parameter to be an underestimate of the HOMO-LUMO gap. "// &
    2228             :                        "This preconditioner is recommended for almost all systems, except very large systems where "// &
    2229             :                        "make_preconditioner would dominate the total computational cost.", &
    2230             :                        "Based on H-eS cholesky inversion, similar to FULL_SINGLE in preconditioning efficiency "// &
    2231             :                        "but cheaper to construct, "// &
    2232             :                        "might be somewhat less robust. Recommended for large systems.", &
    2233             :                        "Based on H-eS diagonalisation, not as good as FULL_ALL, but somewhat cheaper to apply. ", &
    2234             :                        "Cholesky inversion of S and T, fast construction, robust, and relatively good, "// &
    2235             :                        "use for very large systems.", &
    2236             :                        "Cholesky inversion of S, not as good as FULL_KINETIC, yet equally expensive.", &
    2237             :                        "skip preconditioning"), &
    2238             :          enum_i_vals=(/ot_precond_full_all, ot_precond_full_single_inverse, ot_precond_full_single, &
    2239       64282 :                        ot_precond_full_kinetic, ot_precond_s_inverse, ot_precond_none/))
    2240       64282 :       CALL section_add_keyword(section, keyword)
    2241       64282 :       CALL keyword_release(keyword)
    2242             : 
    2243             :       CALL keyword_create(keyword, __LOCATION__, name="ENERGY_GAP", &
    2244             :                           description="Energy gap estimate [a.u.] for preconditioning", &
    2245             :                           usage="ENERGY_GAP 0.1", &
    2246       64282 :                           default_r_val=0.2_dp)
    2247       64282 :       CALL section_add_keyword(section, keyword)
    2248       64282 :       CALL keyword_release(keyword)
    2249             : 
    2250       64282 :    END SUBROUTINE create_low_scaling_cphf
    2251             : 
    2252             : ! **************************************************************************************************
    2253             : !> \brief ...
    2254             : !> \param section ...
    2255             : ! **************************************************************************************************
    2256       64282 :    SUBROUTINE create_mp2_potential(section)
    2257             :       TYPE(section_type), POINTER                        :: section
    2258             : 
    2259             :       TYPE(keyword_type), POINTER                        :: keyword
    2260             : 
    2261       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    2262             :       CALL section_create(section, __LOCATION__, name="INTERACTION_POTENTIAL", &
    2263             :                           description="Parameters the interaction potential in computing the biel integrals", &
    2264       64282 :                           n_keywords=4, n_subsections=0, repeats=.FALSE.)
    2265             : 
    2266       64282 :       NULLIFY (keyword)
    2267             :       CALL keyword_create( &
    2268             :          keyword, __LOCATION__, &
    2269             :          name="POTENTIAL_TYPE", &
    2270             :          description="Which interaction potential should be used "// &
    2271             :          "(Coulomb, TShPSC operator).", &
    2272             :          usage="POTENTIAL_TYPE TSHPSC", &
    2273             :          enum_c_vals=s2a("COULOMB", "TShPSC", "LONGRANGE", "SHORTRANGE", "TRUNCATED", "MIX_CL", "IDENTITY"), &
    2274             :          enum_i_vals=(/do_potential_coulomb, &
    2275             :                        do_potential_TShPSC, &
    2276             :                        do_potential_long, &
    2277             :                        do_potential_short, &
    2278             :                        do_potential_truncated, &
    2279             :                        do_potential_mix_cl, &
    2280             :                        do_potential_id/), &
    2281             :          enum_desc=s2a("Coulomb potential: 1/r", &
    2282             :                        "| Range | TShPSC |"//newline// &
    2283             :                        "| ----- | ------ |"//newline// &
    2284             :                        "| $ x \leq R_c $ | $ 1/x - s/R_c $ |"//newline// &
    2285             :                        "| $ R_c < x \leq nR_c $ | "// &
    2286             :                        "$ (1 - s)/R_c - (x - R_c)/R_c^2 + (x - R_c)^2/R_c^3 - "// &
    2287             :                        "(2n^2 - 7n + 9 - 4s)(x - R_c)^3/(R_c^4(n^2 - 2n + 1)(n - 1)) + "// &
    2288             :                        "(6-3s - 4n + n^2)(x - R_c)^4/(R_c^5(n^4 - 4n^3 + 6n^2 - 4n + 1)) $ "// &
    2289             :                        "(4th order polynomial) | "//newline// &
    2290             :                        "| $ x > nR_c $ | $ 0 $ | "//newline, &
    2291             :                        "Longrange Coulomb potential: $ \operatorname{erf}(wr)/r $", &
    2292             :                        "Shortrange Coulomb potential: $ \operatorname{erfc}(wr)/r $", &
    2293             :                        "Truncated Coulomb potential", &
    2294             :                        "Mixed Coulomb/Longrange Coulomb potential", &
    2295             :                        "Delta potential"), &
    2296       64282 :          default_i_val=do_potential_coulomb)
    2297       64282 :       CALL section_add_keyword(section, keyword)
    2298       64282 :       CALL keyword_release(keyword)
    2299             : 
    2300             :       CALL keyword_create(keyword, __LOCATION__, name="TRUNCATION_RADIUS", &
    2301             :                           variants=(/"CUTOFF_RADIUS"/), &
    2302             :                           description="Determines truncation radius for the truncated potentials. "// &
    2303             :                           "Only valid when doing truncated calculations", &
    2304             :                           usage="TRUNCATION_RADIUS 10.0", type_of_var=real_t, &
    2305             :                           default_r_val=10.0_dp, &
    2306      128564 :                           unit_str="angstrom")
    2307       64282 :       CALL section_add_keyword(section, keyword)
    2308       64282 :       CALL keyword_release(keyword)
    2309             : 
    2310             :       CALL keyword_create( &
    2311             :          keyword, __LOCATION__, &
    2312             :          name="POTENTIAL_DATA", &
    2313             :          variants=s2a("TShPSC_DATA", "T_C_G_DATA"), &
    2314             :          description="Location of the file TShPSC.dat or t_c_g.dat that contains the data for the "// &
    2315             :          "evaluation of the evaluation of the truncated potentials", &
    2316             :          usage="TShPSC_DATA t_sh_p_s_c.dat", &
    2317       64282 :          default_c_val="t_sh_p_s_c.dat")
    2318       64282 :       CALL section_add_keyword(section, keyword)
    2319       64282 :       CALL keyword_release(keyword)
    2320             : 
    2321             :       CALL keyword_create( &
    2322             :          keyword, __LOCATION__, &
    2323             :          name="OMEGA", &
    2324             :          description="Range separation parameter for the longrange or shortrange potential. "// &
    2325             :          "Only valid when longrange or shortrange potential is requested.", &
    2326             :          usage="OMEGA 0.5", type_of_var=real_t, &
    2327       64282 :          default_r_val=0.5_dp)
    2328       64282 :       CALL section_add_keyword(section, keyword)
    2329       64282 :       CALL keyword_release(keyword)
    2330             : 
    2331             :       CALL keyword_create( &
    2332             :          keyword, __LOCATION__, &
    2333             :          name="SCALE_COULOMB", &
    2334             :          description="Scaling factor of (truncated) Coulomb potential in mixed (truncated) Coulomb/Longrange potential. "// &
    2335             :          "Only valid when mixed potential is requested.", &
    2336             :          usage="OMEGA 0.5", type_of_var=real_t, &
    2337       64282 :          default_r_val=1.0_dp)
    2338       64282 :       CALL section_add_keyword(section, keyword)
    2339       64282 :       CALL keyword_release(keyword)
    2340             : 
    2341             :       CALL keyword_create( &
    2342             :          keyword, __LOCATION__, &
    2343             :          name="SCALE_LONGRANGE", &
    2344             :          description="Scaling factor of longrange Coulomb potential in mixed (truncated) Coulomb/Longrange potential. "// &
    2345             :          "Only valid when mixed potential is requested.", &
    2346             :          usage="OMEGA 0.5", type_of_var=real_t, &
    2347       64282 :          default_r_val=1.0_dp)
    2348       64282 :       CALL section_add_keyword(section, keyword)
    2349       64282 :       CALL keyword_release(keyword)
    2350             : 
    2351       64282 :    END SUBROUTINE create_mp2_potential
    2352             : 
    2353             : ! **************************************************************************************************
    2354             : !> \brief ...
    2355             : !> \param section ...
    2356             : ! **************************************************************************************************
    2357       64282 :    SUBROUTINE create_ri_section(section)
    2358             :       TYPE(section_type), POINTER                        :: section
    2359             : 
    2360             :       TYPE(keyword_type), POINTER                        :: keyword
    2361             :       TYPE(section_type), POINTER                        :: subsection
    2362             : 
    2363       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    2364             :       CALL section_create(section, __LOCATION__, name="RI", &
    2365             :                           description="Parameters influencing resolution of the identity (RI) that is "// &
    2366             :                           "used in RI-MP2, RI-RPA, RI-SOS-MP2 and GW (inside RI-RPA).", &
    2367       64282 :                           n_keywords=6, n_subsections=2, repeats=.FALSE.)
    2368             : 
    2369       64282 :       NULLIFY (subsection)
    2370       64282 :       CALL create_RI_metric_section(subsection)
    2371       64282 :       CALL section_add_subsection(section, subsection)
    2372       64282 :       CALL section_release(subsection)
    2373             : 
    2374       64282 :       CALL create_opt_ri_basis(subsection)
    2375       64282 :       CALL section_add_subsection(section, subsection)
    2376       64282 :       CALL section_release(subsection)
    2377             : 
    2378       64282 :       NULLIFY (keyword)
    2379             :       CALL keyword_create( &
    2380             :          keyword, __LOCATION__, &
    2381             :          name="ROW_BLOCK", &
    2382             :          variants=(/"ROW_BLOCK_SIZE"/), &
    2383             :          description="Size of the row block used in the SCALAPACK block cyclic data distribution. "// &
    2384             :          "Default is (ROW_BLOCK=-1) is automatic. "// &
    2385             :          "A proper choice can speedup the parallel matrix multiplication in the case of RI-RPA and RI-SOS-MP2-Laplace.", &
    2386             :          usage="ROW_BLOCK 512", &
    2387      128564 :          default_i_val=-1)
    2388       64282 :       CALL section_add_keyword(section, keyword)
    2389       64282 :       CALL keyword_release(keyword)
    2390             : 
    2391             :       CALL keyword_create( &
    2392             :          keyword, __LOCATION__, &
    2393             :          name="COL_BLOCK", &
    2394             :          variants=(/"COL_BLOCK_SIZE"/), &
    2395             :          description="Size of the column block used in the SCALAPACK block cyclic data distribution. "// &
    2396             :          "Default is (COL_BLOCK=-1) is automatic. "// &
    2397             :          "A proper choice can speedup the parallel matrix multiplication in the case of RI-RPA and RI-SOS-MP2-Laplace.", &
    2398             :          usage="COL_BLOCK 512", &
    2399      128564 :          default_i_val=-1)
    2400       64282 :       CALL section_add_keyword(section, keyword)
    2401       64282 :       CALL keyword_release(keyword)
    2402             : 
    2403             :       CALL keyword_create( &
    2404             :          keyword, __LOCATION__, &
    2405             :          name="CALC_COND_NUM", &
    2406             :          variants=(/"CALC_CONDITION_NUMBER"/), &
    2407             :          description="Calculate the condition number of the (P|Q) matrix for the RI methods.", &
    2408             :          usage="CALC_COND_NUM", &
    2409             :          default_l_val=.FALSE., &
    2410      128564 :          lone_keyword_l_val=.TRUE.)
    2411       64282 :       CALL section_add_keyword(section, keyword)
    2412       64282 :       CALL keyword_release(keyword)
    2413             : 
    2414             :       CALL keyword_create(keyword, __LOCATION__, name="DO_SVD", &
    2415             :                           description="Wether to perform a singular value decomposition instead of the Cholesky decomposition "// &
    2416             :                           "of the potential operator in the RI basis. Computationally expensive but numerically more stable. "// &
    2417             :                           "It reduces the computational costs of some subsequent steps. Recommended when a longrange Coulomb "// &
    2418             :                           "potential is employed.", &
    2419             :                           usage="DO_SVD  .TRUE.", &
    2420       64282 :                           default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
    2421       64282 :       CALL section_add_keyword(section, keyword)
    2422       64282 :       CALL keyword_release(keyword)
    2423             : 
    2424             :       CALL keyword_create(keyword, __LOCATION__, name="ERI_BLKSIZE", &
    2425             :                           description="block sizes for tensors (only used if ERI_METHOD=MME). First value "// &
    2426             :                           "is the block size for ORB basis, second value is the block size for RI_AUX basis.", &
    2427             :                           usage="ERI_BLKSIZE", &
    2428             :                           n_var=2, &
    2429       64282 :                           default_i_vals=(/4, 16/))
    2430       64282 :       CALL section_add_keyword(section, keyword)
    2431       64282 :       CALL keyword_release(keyword)
    2432             : 
    2433       64282 :    END SUBROUTINE create_ri_section
    2434             : 
    2435             : ! **************************************************************************************************
    2436             : !> \brief ...
    2437             : !> \param section ...
    2438             : ! **************************************************************************************************
    2439       64282 :    SUBROUTINE create_integrals_section(section)
    2440             :       TYPE(section_type), POINTER                        :: section
    2441             : 
    2442             :       TYPE(keyword_type), POINTER                        :: keyword
    2443             :       TYPE(section_type), POINTER                        :: subsection
    2444             : 
    2445       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    2446             :       CALL section_create(section, __LOCATION__, name="INTEGRALS", &
    2447             :                           description="Parameters controlling how to compute integrals that are needed "// &
    2448             :                           "in MP2, RI-MP2, RI-RPA, RI-SOS-MP2 and GW (inside RI-RPA).", &
    2449       64282 :                           n_keywords=2, n_subsections=3, repeats=.FALSE.)
    2450             : 
    2451       64282 :       NULLIFY (subsection)
    2452       64282 :       CALL create_eri_mme_section(subsection)
    2453       64282 :       CALL section_add_subsection(section, subsection)
    2454       64282 :       CALL section_release(subsection)
    2455             : 
    2456       64282 :       CALL create_wfc_gpw(subsection)
    2457       64282 :       CALL section_add_subsection(section, subsection)
    2458       64282 :       CALL section_release(subsection)
    2459             : 
    2460       64282 :       CALL create_mp2_potential(subsection)
    2461       64282 :       CALL section_add_subsection(section, subsection)
    2462       64282 :       CALL section_release(subsection)
    2463             : 
    2464       64282 :       NULLIFY (keyword)
    2465             :       CALL keyword_create(keyword, __LOCATION__, name="ERI_METHOD", &
    2466             :                           description="Method for calculating periodic electron repulsion integrals "// &
    2467             :                           "(MME method is faster but experimental, forces not yet implemented). "// &
    2468             :                           "Obara-Saika (OS) for the Coulomb operator can only be used for non-periodic calculations.", &
    2469             :                           usage="ERI_METHOD MME", &
    2470             :                           enum_c_vals=s2a("DEFAULT", "GPW", "MME", "OS"), &
    2471             :                           enum_i_vals=(/eri_default, do_eri_gpw, do_eri_mme, do_eri_os/), &
    2472             :                           enum_desc=s2a("Use default ERI method (for periodic systems: GPW, for molecules: OS, "// &
    2473             :                                         "for MP2 and RI-MP2: GPW in any case).", &
    2474             :                                         "Uses Gaussian Plane Wave method [DelBen2013].", &
    2475             :                                         "Uses MiniMax-Ewald method (experimental, ERI_MME subsection, only for fully periodic "// &
    2476             :                                         "systems with orthorhombic cells).", &
    2477             :                                         "Use analytical Obara-Saika method."), &
    2478       64282 :                           default_i_val=eri_default)
    2479       64282 :       CALL section_add_keyword(section, keyword)
    2480       64282 :       CALL keyword_release(keyword)
    2481             : 
    2482             :       CALL keyword_create(keyword, __LOCATION__, name="SIZE_LATTICE_SUM", &
    2483             :                           description="Size of sum range L. ", &
    2484             :                           usage="SIZE_LATTICE_SUM  10", &
    2485       64282 :                           default_i_val=5)
    2486       64282 :       CALL section_add_keyword(section, keyword)
    2487       64282 :       CALL keyword_release(keyword)
    2488             : 
    2489       64282 :    END SUBROUTINE create_integrals_section
    2490             : 
    2491             : ! **************************************************************************************************
    2492             : !> \brief ...
    2493             : !> \param section ...
    2494             : ! **************************************************************************************************
    2495       64282 :    SUBROUTINE create_RI_metric_section(section)
    2496             :       TYPE(section_type), POINTER                        :: section
    2497             : 
    2498             :       TYPE(keyword_type), POINTER                        :: keyword
    2499             : 
    2500       64282 :       CPASSERT(.NOT. ASSOCIATED(section))
    2501             :       CALL section_create(section, __LOCATION__, name="RI_METRIC", &
    2502             :                           description="Sets up RI metric", &
    2503       64282 :                           repeats=.FALSE.)
    2504             : 
    2505       64282 :       NULLIFY (keyword)
    2506             :       CALL keyword_create( &
    2507             :          keyword, __LOCATION__, &
    2508             :          name="POTENTIAL_TYPE", &
    2509             :          description="Decides which operator/metric is used for resolution of the identity (RI).", &
    2510             :          usage="POTENTIAL_TYPE DEFAULT", &
    2511             :          enum_c_vals=s2a("DEFAULT", "COULOMB", "IDENTITY", "LONGRANGE", "SHORTRANGE", "TRUNCATED"), &
    2512             :          enum_i_vals=(/ri_default, do_potential_coulomb, do_potential_id, do_potential_long, &
    2513             :                        do_potential_short, do_potential_truncated/), &
    2514             :          enum_desc=s2a("Use Coulomb metric for RI-MP2 and normal-scaling RI-SOS-MP2, RI-RPA and GW. "// &
    2515             :                        "Use Overlap metric for low-scaling RI-SOS-MP2, RI-RPA and GW for periodic systems. "// &
    2516             :                        "Use truncated Coulomb metric for low-scaling RI-SOS-MP2, RI-RPA and GW for non-periodic systems.", &
    2517             :                        "Coulomb metric: 1/r. Recommended for RI-MP2,", &
    2518             :                        "Overlap metric: delta(r).", &
    2519             :                        "Longrange metric: erf(omega*r)/r. Not recommended with DO_SVD .TRUE.", &
    2520             :                        "Shortrange metric: erfc(omega*r)/r", &
    2521             :                        "Truncated Coulomb metric: if (r &lt; R_c) 1/r else 0. More "// &
    2522             :                        "accurate than IDENTITY for non-periodic systems. Recommended for low-scaling methods."), &
    2523       64282 :          default_i_val=ri_default)
    2524       64282 :       CALL section_add_keyword(section, keyword)
    2525       64282 :       CALL keyword_release(keyword)
    2526             : 
    2527       64282 :       NULLIFY (keyword)
    2528             :       CALL keyword_create( &
    2529             :          keyword, __LOCATION__, &
    2530             :          name="OMEGA", &
    2531             :          description="The range parameter for the short/long range operator (in 1/a0).", &
    2532             :          usage="OMEGA 0.5", &
    2533       64282 :          default_r_val=0.0_dp)
    2534       64282 :       CALL section_add_keyword(section, keyword)
    2535       64282 :       CALL keyword_release(keyword)
    2536             : 
    2537             :       CALL keyword_create(keyword, __LOCATION__, name="CUTOFF_RADIUS", &
    2538             :                           description="The cutoff radius (in Angstrom) for the truncated Coulomb operator.", &
    2539             :                           usage="CUTOFF_RADIUS 3.0", default_r_val=cp_unit_to_cp2k(value=3.0_dp, unit_str="angstrom"), &
    2540       64282 :                           type_of_var=real_t, unit_str="angstrom")
    2541       64282 :       CALL section_add_keyword(section, keyword)
    2542       64282 :       CALL keyword_release(keyword)
    2543             : 
    2544             :       CALL keyword_create( &
    2545             :          keyword, __LOCATION__, &
    2546             :          name="T_C_G_DATA", &
    2547             :          description="Location of the file t_c_g.dat that contains the data for the "// &
    2548             :          "evaluation of the truncated gamma function ", &
    2549       64282 :          default_c_val="t_c_g.dat")
    2550       64282 :       CALL section_add_keyword(section, keyword)
    2551       64282 :       CALL keyword_release(keyword)
    2552             : 
    2553             :       CALL keyword_create(keyword, __LOCATION__, name="EPS_RANGE", &
    2554             :                           description="The threshold to determine the effective range of the short range "// &
    2555             :                           "RI metric: erfc(omega*eff_range)/eff_range = EPS_RANGE", &
    2556             :                           default_r_val=1.0E-08_dp, &
    2557       64282 :                           repeats=.FALSE.)
    2558       64282 :       CALL section_add_keyword(section, keyword)
    2559       64282 :       CALL keyword_release(keyword)
    2560             : 
    2561       64282 :    END SUBROUTINE create_RI_metric_section
    2562             : 
    2563             : END MODULE input_cp2k_mp2

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