Equilibrium volume of Si in the RPA: Difference between revisions
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=== Step 1 === | === Step 1 === | ||
*DFT groundstate calculation with a “dense” mesh of k-points | *DFT groundstate calculation with a “dense” mesh of k-points | ||
*The following {{TAG|INCAR}} file is used (INCAR.DFT): | *The following {{TAG|INCAR}} file is used (INCAR.DFT): | ||
| Line 44: | Line 43: | ||
12 12 12 | 12 12 12 | ||
0 0 0 | 0 0 0 | ||
=== Step 2 === | |||
*Compute the Hartree-Fock energy using the DFT orbitals of Step 1. | |||
*The {{TAG|INCAR}} file INCAR.EXX is used in this step: | |||
{{TAGBL|ALGO}} = EIGENVAL ; {{TAGBL|NELM}} = 1 | |||
{{TAGBL|LWAVE}} = .FALSE. | |||
{{TAGBL|LHFCALC}} = .TRUE. | |||
{{TAGBL|AEXX}} = 1.0 ; {{TAGBL|ALDAC}} = 0.0 ; {{TAGBL|AGGAC}} = 0.0 | |||
{{TAGBL|NKRED}} = 2 | |||
{{TAGBL|ISMEAR}} = 0 ; {{TAGBL|SIGMA}} = 0.05 | |||
{{TAGBL|KPAR}} = 8 | |||
{{TAGBL|NBANDS}} = 4 | |||
---- | ---- | ||
== Used INCAR Tags == | == Used INCAR Tags == | ||
Revision as of 09:57, 3 April 2018
Overview > bandgap of Si in GW > bandstructure of Si in GW (VASP2WANNIER90) > bandstructure of SrVO3 in GW > CRPA of SrVO3 > Equilibrium volume of Si in the RPA > List of tutorials
Task
Calculation of the equilibrium lattice constant of Si in the RPA (ACFDT).
Input
POSCAR
system Si 5.8 0.5 0.5 0.0 0.0 0.5 0.5 0.5 0.0 0.5 2 cart 0.00 0.00 0.00 0.25 0.25 0.25
Calculation
The workflow of RPA total energy calculations consists of five consecutive steps:
- Step 1: a “standard” DFT groundstate calculation with a “dense” mesh of k-points.
- Step 2: compute the Hartree-Fock energy using the orbitals of Step 1. Needs WAVECAR file from step 1.
- Step 3: a “standard” DFT groundstate calculation with “coarse” mesh of k-points.
- Step 4: obtain DFT “virtual” orbitals (empty states). Needs WAVECAR file from step 3.
- Step 5: the RPA correlation energy (ACFDT) calculation. Needs WAVECAR and WAVEDER files from step 4.
In case of metallic systems there is an additional step between Steps 4 and 5, that is beyond the scope of this example.
All of the calculation steps are prepared in the script doall.sh.
Step 1
- DFT groundstate calculation with a “dense” mesh of k-points
- The following INCAR file is used (INCAR.DFT):
ISMEAR = 0 ; SIGMA = 0.05 EDIFF = 1E-8
- The following POSCAR file is used (KPOINTS.12):
12x12x12 0 G 12 12 12 0 0 0
Step 2
- Compute the Hartree-Fock energy using the DFT orbitals of Step 1.
- The INCAR file INCAR.EXX is used in this step:
ALGO = EIGENVAL ; NELM = 1 LWAVE = .FALSE. LHFCALC = .TRUE. AEXX = 1.0 ; ALDAC = 0.0 ; AGGAC = 0.0 NKRED = 2 ISMEAR = 0 ; SIGMA = 0.05 KPAR = 8 NBANDS = 4
Used INCAR Tags
AEXX, AGGAC, ALDAC, ALGO, EDIFF, ISMEAR, KPAR, LHFCALC, LOPTICS, LWAVE, NBANDS, NELM, NKRED, NOMEGA, SIGMA, SYSTEM
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Overview > bandgap of Si in GW > bandstructure of Si in GW (VASP2WANNIER90) > bandstructure of SrVO3 in GW > CRPA of SrVO3 > Equilibrium volume of Si in the RPA > List of tutorials
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