howto:dft_u
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How to run a DFT+U calculation
Example: EOS calculation for cubic FeO
The following CP2K input file is an example how an equation of state (EOS) calculation for cubic FeO (space group #225) can be performed:
# FeO (#225, Fm-3m, wustite, antiferromagnetic along [111])
# f094 = 0.94^(1/3) .. f120 = 1.20^(1/3)
@SET f094 0.9795861087155615099
@SET f096 0.9864848297321880954
@SET f098 0.9932883883792685831
@SET f100 1.0000000000000000000
@SET f102 1.0066227095601130159
@SET f104 1.0131594038201774399
@SET f106 1.0196128224222165137
@SET f108 1.0259855680060181936
@SET f110 1.0322801154563671592
@SET f112 1.0384988203702208052
@SET f120 1.0626585691826110661
@SET run_type energy_force
@SET system FeO
@SET project ${system}-2x2x2
@SET a 8.56*${f100}
@SET b ${a}
@SET c ${a}
@SET a_ref ${a}*${f120}
@SET b_ref ${a_ref}
@SET c_ref ${a_ref}
@SET PLUS_U on
@SET U_Fe 1.9
&GLOBAL
PRINT_LEVEL low
PROJECT ${project}
RUN_TYPE ${run_type}
WALLTIME 1800
&END GLOBAL
&FORCE_EVAL
METHOD Quickstep
&DFT
LSD
PLUS_U_METHOD Mulliken
BASIS_SET_FILE_NAME BASIS_MOLOPT
POTENTIAL_FILE_NAME GTH_POTENTIALS
&MGRID
CUTOFF 600.0
REL_CUTOFF 60.0
&END MGRID
&QS
EPS_DEFAULT 1.0E-12
&END QS
&SCF
EPS_SCF 3.0E-7
MAX_SCF 21
SCF_GUESS restart
&OT on
MINIMIZER CG
PRECONDITIONER FULL_SINGLE_INVERSE
STEPSIZE 0.1
&END OT
&OUTER_SCF on
EPS_SCF 3.0E-7
MAX_SCF 20
&END OUTER_SCF
&PRINT
&RESTART
BACKUP_COPIES 0
&EACH
QS_SCF 10
&END EACH
&END RESTART
&END PRINT
&END SCF
&XC
&XC_FUNCTIONAL PBE
&END XC_FUNCTIONAL
&END XC
&END DFT
&SUBSYS
&CELL
ABC ${a} ${b} ${c}
&CELL_REF
ABC ${a_ref} ${b_ref} ${c_ref}
&END CELL_REF
&END CELL
&COORD
SCALED
Fe_a 0 0 0
Fe_b 0 1/4 1/4
Fe_b 1/4 0 1/4
Fe_b 1/4 1/4 0
Fe_b 0 0 1/2
Fe_b 1/2 0 0
Fe_b 0 1/2 0
Fe_a 0 1/4 3/4
Fe_a 1/2 1/4 1/4
Fe_a 0 3/4 1/4
Fe_a 1/4 0 3/4
Fe_a 3/4 0 1/4
Fe_a 1/4 1/2 1/4
Fe_a 1/4 1/4 1/2
Fe_a 3/4 1/4 0
Fe_a 1/4 3/4 0
Fe_a 0 1/2 1/2
Fe_a 1/2 0 1/2
Fe_a 1/2 1/2 0
Fe_b 0 3/4 3/4
Fe_b 1/2 1/4 3/4
Fe_b 1/2 3/4 1/4
Fe_b 1/4 1/2 3/4
Fe_b 3/4 0 3/4
Fe_b 3/4 1/2 1/4
Fe_b 1/4 3/4 1/2
Fe_b 3/4 1/4 1/2
Fe_b 3/4 3/4 0
Fe_b 1/2 1/2 1/2
Fe_a 1/2 3/4 3/4
Fe_a 3/4 1/2 3/4
Fe_a 3/4 3/4 1/2
O 1/4 1/4 1/4
O 3/4 3/4 3/4
O 3/4 3/4 1/4
O 1/4 1/4 3/4
O 3/4 1/4 3/4
O 1/4 3/4 1/4
O 1/4 3/4 3/4
O 3/4 1/4 1/4
O 1/4 1/2 1/2
O 3/4 0 0
O 3/4 0 1/2
O 1/4 1/2 0
O 3/4 1/2 0
O 1/4 0 1/2
O 1/4 0 0
O 3/4 1/2 1/2
O 1/2 1/4 1/2
O 0 3/4 0
O 0 3/4 1/2
O 1/2 1/4 0
O 0 1/4 0
O 1/2 3/4 1/2
O 1/2 3/4 0
O 0 1/4 1/2
O 1/2 1/2 1/4
O 0 0 3/4
O 0 0 1/4
O 1/2 1/2 3/4
O 0 1/2 3/4
O 1/2 0 1/4
O 1/2 0 3/4
O 0 1/2 1/4
&END COORD
&KIND O
BASIS_SET DZVP-MOLOPT-SR-GTH-q6
POTENTIAL GTH-PBE-q6
# O(2-): 2s2 2p6
&BS on
&ALPHA
N 2
L 1
NEL 2
&END ALPHA
&BETA
N 2
L 1
NEL 2
&END BETA
&END BS
&END KIND
&KIND Fe_a
BASIS_SET DZVP-MOLOPT-SR-GTH-q16
POTENTIAL GTH-PBE-q16
# Fe(2+): 3d6 (alpha, spin up)
&BS on
&ALPHA
N 4 3
L 0 2
NEL -2 4
&END ALPHA
&BETA
N 4 3
L 0 2
NEL -2 -4
&END BETA
&END BS
&DFT_PLUS_U on
L 2
U_MINUS_J [eV] ${U_Fe}
&END DFT_PLUS_U
&END KIND
&KIND Fe_b
BASIS_SET DZVP-MOLOPT-SR-GTH-q16
POTENTIAL GTH-PBE-q16
# Fe(2+); 3d6 (beta, spin down)
&BS on
&ALPHA
N 4 3
L 0 2
NEL -2 -4
&END ALPHA
&BETA
N 4 3
L 0 2
NEL -2 4
&END BETA
&END BS
&DFT_PLUS_U on
L 2
U_MINUS_J [eV] ${U_Fe}
&END DFT_PLUS_U
&END KIND
&END SUBSYS
&END FORCE_EVAL
howto/dft_u.1700729976.txt.gz · Last modified: 2023/11/23 08:59 by krack