exercises:2015_pitt:gga
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+ | ====== GGA based surface science ====== | ||
+ | |||
+ | GGA DFT calculations can be performed with CP2K relatively easily for many systems. While the CP2K {{ http:// | ||
+ | |||
+ | Crucial to start are a reasonable initial structure, and for condensed phase systems the size of the simulation cell. Once these are known, copy& | ||
+ | |||
+ | Among the important parameters of the simulations are: | ||
+ | * model (structure) | ||
+ | * Gaussian basis set | ||
+ | * Plane Waves (PW) cutoff | ||
+ | * Density functional | ||
+ | |||
+ | Assessing the influence of these parameters might be more challenging. | ||
+ | |||
====== Dye anchoring to TiO$_2$ ====== | ====== Dye anchoring to TiO$_2$ ====== | ||
- | In this exercise you will compare two possible binding modes of acetic acid to anatase TiO$_2$. Acetic acid contains the carboxylic group. It is commonly used in [[wp> | ||
- | {{ dye2.png? | + | In this exercise you will compare two possible binding modes of acetic acid to anatase TiO$_2$. Acetic acid contains the carboxylic group. It is commonly used in [[wp> |
- | ===== 1. Task: Familiarize yourself | + | {{ exercises:2015_ethz_mmm: |
- | The coordinate of the two binding modes are provided you as '' | + | |
- | ===== 2. Task: Bond induced density differences | + | ===== 1. Task: Familiarize yourself with system and setup ===== |
- | Compute the density difference induced by the bonding for the first binding mode. | + | |
- | For this you will have to run three separate energy calculations: | + | |
- | - combined system bound in the first mode (file '' | + | |
- | - lone acetic acid molecule (just remove slab's coordinates from '' | + | |
- | - lone TiO$_2$ slab (just remove the acid's coordinates from '' | + | |
- | In order to output | + | * Use vmd to vizualize |
- | <code> | + | * To edit the input files provided below, use an editor such as '' |
- | &DFT | + | |
- | | + | * Use a job script to submit jobs on the cluster, an example job submission script might look like |
- | & | + | |
- | &END E_DENSITY_CUBE | + | |
- | &END | + | |
- | &END DFT | + | |
- | </code> | + | |
- | <note tip> | + | <code - job> |
- | The calculations involving the large TiO$_2$ slab should be run on 16 nodes with '' | + | #PBS -N mode1 |
- | </ | + | #PBS -j oe |
+ | #PBS -q dist_small | ||
+ | #PBS -l nodes=4: | ||
+ | #PBS -l walltime=10: | ||
+ | #PBS -A cp2k2015 | ||
- | To process the cube files we are going to use the cubecruncher tool. It is part of CP2K, but not installed on brutus. | + | cd $PBS_O_WORKDIR |
- | Therefore, a compiled binary of the tool is provided at ''/ | + | |
- | < | + | module purge |
- | you@brutusX ~$ ln -s / | + | module |
+ | |||
+ | prun cp2k.popt | ||
</ | </ | ||
- | Now subtract | + | ===== 2. Task: Binding induced density differences ===== |
+ | |||
+ | We start with single point energy calculations on binding mode 1, to visualize | ||
+ | |||
+ | \[ \rho_\text{induced}= \rho_\text{slab-dye-complex} - \rho_\text{dye} - \rho_\text{slab} \] | ||
+ | |||
+ | First, we'll discuss in detail | ||
+ | |||
+ | topics: | ||
+ | * Project name | ||
+ | * Runtype | ||
+ | * Gaussian Basis, pseudopotentials | ||
+ | * PW Cutoff | ||
+ | * thresholds | ||
+ | * SCF: OT | ||
+ | * XC and -D3 correction | ||
+ | * Unit cell choice | ||
+ | |||
+ | Second, we run the cp2k input and store the output for analysis and discussion. | ||
< | < | ||
- | you@brutusX ~$ ./ | + | cp2k.popt -i mode1.inp -o mode1.out |
- | you@brutusX ~$ ./ | + | |
</ | </ | ||
+ | In addition to the output '' | ||
- | The generated | + | topics: |
+ | * General overiew | ||
+ | * OT output | ||
+ | * Various grid quantities | ||
+ | * Density | ||
+ | * Timing report | ||
+ | |||
+ | Third, we compute the changes in density induced by the binding. For this you will have to run three separate energy calculations: | ||
+ | - combined system bound in the first mode (file '' | ||
+ | - lone acetic acid molecule (just remove slab's coordinates from '' | ||
+ | - lone TiO$_2$ slab (just remove the acid's coordinates from '' | ||
+ | |||
+ | Create the .xyz files (check | ||
+ | |||
+ | After computing these input files, we analyze the results using a tool provided with cp2k '' | ||
< | < | ||
- | you@brutusX | + | ~$ cubecruncher.x -i MODE1-ELECTRON_DENSITY-1_0.cube -subtract MODE1_dye-ELECTRON_DENSITY-1_0.cube -o tmp.cube |
+ | ~$ cubecruncher.x | ||
</ | </ | ||
- | You can visualize the resulting file '' | + | You can visualize the resulting file '' |
What you get should look similar to this: | What you get should look similar to this: | ||
- | {{ dye_tio_bonding_density.png? | + | {{ exercises: |
+ | |||
+ | ===== 3. Task: relative stabilities | ||
+ | |||
+ | In order to compute the relative stability of mode1 and mode2, both configurations need to be geometry optimized. | ||
- | ===== 3. Task: Bonding energies | + | To do so, turn off the generation of cubes (''& |
- | Compute | + | |
- | \[ E_\text{binding}=\sum E_\text{products} - \sum E_\text{reactants} \] | + | input topics: |
+ | * BFGS vs LBFGS | ||
+ | * EPS_SCF, CUTOFF, MAX_DR, .. | ||
- | For this you will need the energy values of four systems: | + | output topics: |
- | | + | |
- | - lone TiO$_2$ slab (you can use the already geometry optimized coordinates from '' | + | |
- | - combined system bound in the first mode (can be reused from previous task) | + | |
- | | + | |
- | <note important> | + | Compare |
- | You can not reuse the energy | + | ===== 4. Task: ab initio molecular dynamics |
- | [[geometry_optimization|previous exercise]]. | + | |
- | </ | + | |
+ | < | ||
- | ===== Questions ===== | + | Perform a short ab initio molecular dynamics simulation of the system |
- | * Sketch briefly the two binding modes. | + | |
- | * Report | + | |
- | * Which binding mode is more stable? | + | |
- | * Briefly report | + | |
- | ===== Required Files ===== | + | {{exercises: |
- | <note tip> When you are dealing with big systems and multiple atomic species, the input can be simplified by splitting it into multiple files. We are going to use separate files for the coordinates, | + | |
- | <note warning> | + | What can you say about the hydrogen bond to the surface, relative acidity |
- | The provided [[wp> | + | Note that, in order to be statistically relevant, longer trajectories should be employed, and surface slab thickness will play an important role. Also compare to Fig. 7 of the paper referenced. |
- | </ | + | ====== Required Files ====== |
+ | (right) click on the filename to download to your local machine. | ||
<code - mode1.inp> | <code - mode1.inp> | ||
&GLOBAL | &GLOBAL | ||
- | ! change | + | ! the project |
- | PROJECT | + | PROJECT |
+ | ! various runtypes (energy, geo_opt, etc.) available. | ||
RUN_TYPE ENERGY | RUN_TYPE ENERGY | ||
&END GLOBAL | &END GLOBAL | ||
& | & | ||
+ | ! the electronic structure part of CP2K is named Quickstep | ||
METHOD Quickstep | METHOD Quickstep | ||
&DFT | &DFT | ||
+ | ! basis sets and pseudopotential files can be found in cp2k/data | ||
+ | BASIS_SET_FILE_NAME BASIS_MOLOPT | ||
+ | POTENTIAL_FILE_NAME GTH_POTENTIALS | ||
+ | |||
+ | ! Charge and multiplicity | ||
+ | CHARGE 0 | ||
+ | MULTIPLICITY 1 | ||
+ | |||
+ | &MGRID | ||
+ | ! PW cutoff ... depends on the element (basis) too small cutoffs lead to the eggbox effect. | ||
+ | ! certain calculations (e.g. geometry optimization, | ||
+ | ! NPT and cell optimizations, | ||
+ | | ||
+ | &END | ||
+ | |||
+ | &QS | ||
+ | ! use the GPW method (i.e. pseudopotential based calculations with the Gaussian and Plane Waves scheme). | ||
+ | | ||
+ | ! default threshold for numerics ~ roughly numerical accuracy of the total energy per electron, | ||
+ | ! sets reasonable values for all other thresholds. | ||
+ | | ||
+ | ! used for MD, the method used to generate the initial guess. | ||
+ | | ||
+ | &END | ||
+ | |||
+ | & | ||
+ | | ||
+ | &END | ||
- | & | + | |
+ | & | ||
& | & | ||
&END | &END | ||
- | | + | ! use the OT METHOD for robust and efficient SCF, suitable for all non-metallic systems. |
- | | + | |
- | | + | |
- | ! This keyword refers the input to an external potential file, which has to be in the same directory as this input file | + | |
- | + | | |
- | & | + | |
- | MAX_SCF 50 | + | |
&OT | &OT | ||
+ | ! an accurate preconditioner suitable also for larger systems | ||
PRECONDITIONER FULL_SINGLE_INVERSE | PRECONDITIONER FULL_SINGLE_INVERSE | ||
+ | ! the most robust choice (DIIS might sometimes be faster, but not as stable). | ||
+ | MINIMIZER CG | ||
&END OT | &END OT | ||
- | & | + | & |
MAX_SCF 10 | MAX_SCF 10 | ||
+ | EPS_SCF 1.0E-6 ! must match the above | ||
&END | &END | ||
&END SCF | &END SCF | ||
+ | ! specify the exchange and correlation treatment | ||
&XC | &XC | ||
- | & | + | |
+ | | ||
+ | &PBE | ||
+ | & | ||
&END XC_FUNCTIONAL | &END XC_FUNCTIONAL | ||
+ | ! adding Grimme' | ||
+ | & | ||
+ | | ||
+ | & | ||
+ | PARAMETER_FILE_NAME dftd3.dat | ||
+ | TYPE DFTD3 | ||
+ | REFERENCE_FUNCTIONAL PBE | ||
+ | R_CUTOFF [angstrom] 16 | ||
+ | & | ||
+ | &END VDW_POTENTIAL | ||
&END XC | &END XC | ||
- | |||
- | |||
&END DFT | &END DFT | ||
- | | + | |
+ | ! description of the system | ||
&SUBSYS | &SUBSYS | ||
- | &CELL | + | & |
- | ABC 10.2270 11.3460 20.000 | + | ! unit cells that are orthorhombic are more efficient with CP2K |
+ | ABC [angstrom] | ||
&END CELL | &END CELL | ||
- | &COORD | + | |
- | | + | ! atom coordinates |
- | ! Here you either manually insert the coordinates | + | ! or provided as an external file. |
- | @INCLUDE ' | + | & |
- | ! The file should be similar to an *.xyz file but without the total number of atoms at the beginning | + | COORD_FILE_NAME mode1.xyz |
- | + | | |
- | | + | &END |
- | | + | |
- | BASIS_SET | + | ! MOLOPT |
- | POTENTIAL GTH-PBE-q1 | + | ! but in the 'DZVP-MOLOPT-SR-GTH' available for all elements |
+ | | ||
+ | ! for condensed and gas phase systems alike. | ||
+ | &KIND H | ||
+ | BASIS_SET | ||
+ | POTENTIAL GTH-PBE-q1 | ||
&END KIND | &END KIND | ||
&KIND C | &KIND C | ||
- | BASIS_SET DZVP-MOLOPT-GTH | + | BASIS_SET DZVP-MOLOPT-SR-GTH |
POTENTIAL GTH-PBE-q4 | POTENTIAL GTH-PBE-q4 | ||
&END KIND | &END KIND | ||
&KIND O | &KIND O | ||
- | BASIS_SET DZVP-MOLOPT-GTH | + | BASIS_SET DZVP-MOLOPT-SR-GTH |
POTENTIAL GTH-PBE-q6 | POTENTIAL GTH-PBE-q6 | ||
&END KIND | &END KIND | ||
Line 152: | Line 244: | ||
&END FORCE_EVAL | &END FORCE_EVAL | ||
+ | ! how to propagate the system, selection via RUN_TYPE in the &GLOBAL section | ||
+ | &MOTION | ||
+ | & | ||
+ | | ||
+ | | ||
+ | | ||
+ | & | ||
+ | & | ||
+ | & | ||
+ | & | ||
+ | | ||
+ | | ||
+ | | ||
+ | STEPS 1000 | ||
+ | # GLE thermostat as generated at http:// | ||
+ | # GLE provides an effective NVT sampling. | ||
+ | & | ||
+ | | ||
+ | TYPE GLE | ||
+ | & | ||
+ | NDIM 5 | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | & | ||
+ | & | ||
+ | & | ||
+ | &END | ||
</ | </ | ||
- | |||
- | <code - POTENTIALS> | ||
- | ################################################################################ | ||
- | # | ||
- | # Potential data base file for CP2K (Quickstep) | ||
- | # | ||
- | ################################################################################ | ||
- | # ----------------------------------------------------- | ||
- | # | ||
- | # Literature: - S. Goedecker, M. Teter, and J. Hutter, | ||
- | # Phys. Rev. B 54, 1703 (1996) | ||
- | # - C. Hartwigsen, S. Goedecker, and J. Hutter, | ||
- | # Phys. Rev. B 58, 3641 (1998) | ||
- | # - M. Krack, | ||
- | # | ||
- | # | ||
- | # Potential for the PBE functional | ||
- | # | ||
- | ################################################################################ | ||
- | # | ||
- | H GTH-PBE-q1 | ||
- | 1 | ||
- | | ||
- | 0 | ||
- | # | ||
- | C GTH-PBE-q4 | ||
- | 2 2 | ||
- | | ||
- | 2 | ||
- | | ||
- | | ||
- | # | ||
- | O GTH-PBE-q6 | ||
- | 2 4 | ||
- | | ||
- | 2 | ||
- | | ||
- | | ||
- | # | ||
- | Ti GTH-PBE-q12 | ||
- | 4 6 2 | ||
- | | ||
- | 3 | ||
- | | ||
- | | ||
- | | ||
- | -10.49616087 | ||
- | | ||
- | |||
- | </ | ||
- | |||
- | <code - BASIS_SETS> | ||
- | ######################################################################### | ||
- | # | ||
- | # This is a library of molecularly optimised basis functions as described in the paper: | ||
- | # | ||
- | # Gaussian basis sets for accurate calculations on molecular systems | ||
- | # in gas and condensed phases | ||
- | # | ||
- | # Joost VandeVondele and Juerg Hutter | ||
- | # J. Chem. Phys. 127, 114105 (2007) | ||
- | # | ||
- | # URL: http:// | ||
- | # DOI: 10.1063/ | ||
- | # | ||
- | ########################################### | ||
- | | ||
- | 1 | ||
- | 2 0 1 7 2 1 | ||
- | | ||
- | 3.700758562763 | ||
- | 1.446884268432 | ||
- | 0.716814589696 | ||
- | 0.247918564176 | ||
- | 0.066918004004 | ||
- | 0.021708243634 -0.001125195500 -0.059693171300 | ||
- | | ||
- | 1 | ||
- | 2 0 2 7 2 2 1 | ||
- | 6.132624767898 -0.105576563700 | ||
- | 2.625196064782 -0.174866621100 | ||
- | 1.045456957247 | ||
- | 0.478316330874 | ||
- | 0.178617414302 | ||
- | 0.075144725465 | ||
- | 0.030286753006 | ||
- | | ||
- | 1 | ||
- | 2 0 2 7 2 2 1 | ||
- | | ||
- | 5.108150287385 -0.129597923300 | ||
- | 2.048398039874 | ||
- | 0.832381575582 | ||
- | 0.352316246455 | ||
- | 0.142977330880 | ||
- | | ||
- | Ti DZVP-MOLOPT-SR-GTH DZVP-MOLOPT-SR-GTH-q12 | ||
- | 1 | ||
- | 2 0 3 6 3 2 2 1 | ||
- | 7.884569925997 | ||
- | 3.894698463070 | ||
- | 1.513588828959 -0.664995883766 -0.256641947580 | ||
- | 0.596768079836 -0.726044574739 -0.451591547817 | ||
- | 0.222222125842 -0.029011079755 | ||
- | 0.077078461321 | ||
- | |||
- | </ | ||
<code - mode1.xyz> | <code - mode1.xyz> | ||
Line 380: | Line 396: | ||
O -1.5275649623 | O -1.5275649623 | ||
H -1.0670534373 | H -1.0670534373 | ||
- | |||
</ | </ | ||
Line 502: | Line 517: | ||
O -2.9500441444 | O -2.9500441444 | ||
H -0.3897742635 | H -0.3897742635 | ||
- | </ | ||
- | |||
- | <code - relaxed_slab.xyz> | ||
- | 108 | ||
- | |||
- | Ti | ||
- | O | ||
- | Ti | ||
- | O -1.7917634261 | ||
- | O -3.2061730694 | ||
- | O -1.7223354624 | ||
- | Ti | ||
- | O | ||
- | Ti 3.7576915752 | ||
- | O | ||
- | O -4.6411313870 | ||
- | O -5.3047652050 | ||
- | Ti | ||
- | O | ||
- | Ti | ||
- | O -1.7918422000 | ||
- | O -3.2061826485 | ||
- | O -1.7223161680 | ||
- | Ti | ||
- | O | ||
- | Ti 3.7576114879 | ||
- | O | ||
- | O -4.6411391763 | ||
- | O -5.3047626840 | ||
- | Ti | ||
- | O | ||
- | Ti | ||
- | O -1.7918406363 | ||
- | O -3.2061760961 | ||
- | O -1.7223390903 | ||
- | Ti | ||
- | O | ||
- | Ti 3.7576703685 | ||
- | O | ||
- | O -4.6411291967 | ||
- | O -5.3047626859 | ||
- | Ti | ||
- | O -1.0530794682 | ||
- | Ti | ||
- | O -3.3233955054 | ||
- | O -4.7234020378 | ||
- | O -3.2337827875 | ||
- | Ti | ||
- | O -1.1292018546 | ||
- | Ti 2.2748016978 | ||
- | O | ||
- | O | ||
- | O | ||
- | Ti | ||
- | O -1.0531792321 | ||
- | Ti | ||
- | O -3.3234176494 | ||
- | O -4.7234014156 | ||
- | O -3.2338808261 | ||
- | Ti | ||
- | O -1.1292133652 | ||
- | Ti 2.2753347025 | ||
- | O | ||
- | O | ||
- | O | ||
- | Ti | ||
- | O -1.0531788180 | ||
- | Ti | ||
- | O -3.3234140545 | ||
- | O -4.7234083483 | ||
- | O -3.2338028141 | ||
- | Ti | ||
- | O -1.1292026624 | ||
- | Ti 2.2752985947 | ||
- | O | ||
- | O | ||
- | O | ||
- | Ti 1.4062179326 | ||
- | O -2.6647908793 | ||
- | Ti | ||
- | O -0.1912654580 | ||
- | O | ||
- | O -4.8135555127 | ||
- | Ti 3.5973231742 | ||
- | O | ||
- | Ti 0.8351562937 | ||
- | O | ||
- | O | ||
- | O | ||
- | Ti 1.4062978231 | ||
- | O -2.6648159269 | ||
- | Ti | ||
- | O -0.1912655926 | ||
- | O | ||
- | O -4.8135568089 | ||
- | Ti 3.5973007930 | ||
- | O | ||
- | Ti 0.8351415277 | ||
- | O | ||
- | O | ||
- | O | ||
- | Ti 1.4062636238 | ||
- | O -2.6648052713 | ||
- | Ti | ||
- | O -0.1912672794 | ||
- | O | ||
- | O -4.8135603835 | ||
- | Ti 3.5972989622 | ||
- | O | ||
- | Ti 0.8351502243 | ||
- | O | ||
- | O | ||
- | O | ||
</ | </ |
exercises/2015_pitt/gga.1424876793.txt.gz · Last modified: 2020/08/21 10:14 (external edit)