This patch adds the ability to use vdW-DF2-C09 exchange correlation functional to VASP (v.5.4.4)
- Download and apply the official patch for version-5.4.4.16052018.
patch -p0 < patch.5.4.4.16052018
- Apply patch provided by this repo
DF2_C09.patch:
patch -p0 < DF2_C09.patch
- Compile VASP as usual.
To use DF2-C09, simply add the following tags to your INCAR file:
GGA = C9
LUSE_VDW = .TRUE.
PARAM1 = 0.0617
PARAM2 = 1.245
PARAM3 = 0.0483
Zab_vdW = -1.8867
AGGAC = 0.0000
LASPH = .TRUE.
Here, PARAM1 is \mu, PARAM2 is \kappa and PARAM3 is \alpha in equation 3 in this paper.
Also, don't forget the vdw_kernel.bindat file.
The correctness of this patch was checked by comparing the lattice constants of GaSe to the reported results. The calculation was performed with the following parameters:
- ENCUT = 680
- EDIFFG = -0.002
- EDIFF = 1E-6
- KPOINTS= gamma centered 12x12x2
| Literature | a (\AA) | c (\AA) | This implementation | a (\AA) | c (\AA) |
|---|---|---|---|---|---|
| LDA | 3.719 | 15.611 | LDA | 3.717 | 15.647 |
| PBE | 3.823 | 17.848 | PBE | 3.817 | 18.145 |
| vdw-DF2 | 3.946 | 16.511 | vdw-DF2 | 3.959 | 16.577 |
| rev-vdW-DF2 | 3.788 | 16.073 | rev-vdW-DF2 | 3.792 | 16.028 |
| vdW-DF2-C09 | 3.761 | 15.943 | vdW-DF2-C09 | 3.767 | 15.901 |
| PBE-D2 | 3.749 | 15.931 | PBE-D2 | 3.745 | 15.927 |
Any result obtained by this patch should be carefully checked by the user.