About the available functionals in VASP for dftd3.

[hszhao.cn@gmail.com]

Hi VASP team,

For dftd3, there are so many available functionals with different parameter settings, as given here. Therefore, I would like to know which of those functionals are currently supported by VASP when using dftd3.

See here for the related discussion.

Regards,
Zhao

[fabien_tran1]

Hello,

The functionals for which it is not necessary to specify explicitly the DFT-D3 parameters in INCAR are all those listed in the subroutine readparam in subdftd3.F (except BP that was removed from VASP): PBE, RPBE, revPBE, PBEsol, PBE0, B3LYP, HF, TPSS, M06L and SCAN.

For all other functionals, one just need to specify the DFT-D3 parameters in INCAR.

[hszhao.cn@gmail.com]

Here is a potentially incomplete list used by pymatgen, and it is not completely targeted at DFTD3.

[hszhao.cn@gmail.com]

See here for the related discussion.

[hszhao.cn@gmail.com]

The functionals for which it is not necessary to specify explicitly the DFT-D3 parameters in INCAR are all those listed in the subroutine readparam in subdftd3.F (except BP that was removed from VASP): PBE, RPBE, revPBE, PBEsol, PBE0, B3LYP, HF, TPSS, M06L and SCAN.

For all other functionals, one just need to specify the DFT-D3 parameters in INCAR.

1. Do you mean, for BP, I also need to specify the DFT-D3 parameters in INCAR if I want to use it?
2. As you can see, in most cases, the parameters' names of these functionals are inconsistent with the VASP INCAR tags, so, how can I easily find the corresponding INCAR tags for them?

[fabien_tran1]

Yes, the DFT-D3 parameters for BP need to be specified in INCAR. Note also, that since BP was removed from VASP, it has to be specified via Libxc website.

Until VASP version 6.4.2, the string in the source code for the GGA tag was restricted to two characters, i.e., the name of GGA functionals had to be modified (e.g., PBE -> PE).

In order to know how to specify the (GGA, MGGA or hybrid) functional, you need to search for the reference of this functional into the paper where the DFT-D3 parameters were proposed. Then, this should in principle help you to identify the corresponding functional name, either at GGA, METAGGA or on the Libxc website.

[hszhao.cn@gmail.com]

Perhaps my expression of the second question here is not very clear. What I meant to say is, for example, the relevant settings of dftd3 correspond to the following:

Code: Select all

[parameter.b2plyp]
d3.bj = {a1=0.3065, s8=0.9147, a2=5.0570, s6=0.64}
d3.zero = {rs6=1.427, s8=1.022, s6=0.64}
d3.bjm = {a1=0.486434, s8=0.672820, a2=3.656466, s6=0.64, doi="10.1021/acs.jpclett.6b00780"}
d3.zerom = {rs6=1.313134, s8=0.717543, bet=0.016035, s6=0.64, doi="10.1021/acs.jpclett.6b00780"}

For preparing the input files for VASP, I need to determine the corresponding tags in the INCAR file for setting the corresponding parameters such as a1, a2, ..., s8. Some of these have an intuitive corresponding relationship when setting them in the INCAR file, while others do not. For example, what the corresponding tag for bet is in the INCAR file? This is the question I originally intended to express.

[fabien_tran1]

Ok, I misunderstood the question.

d3.bj and d3.bjm:
The parameters a1, s8 and a2 correspond to VDW_A1, VDW_S8 and VDW_A2, respectively. As far as I understood, it should be the same for d3.bjm.

d3.zero:
The parameters rs6 and s8 correspond to VDW_SR and VDW_S8, respectively.

d3.zerom:
This method can not be used, since the parameter bet is not implemented in VASP. Maybe in the future.

For all DFT-D3 methods, the parameter s6 can not be modified, which is however not really a problem since s6 is different from the fixed value s6=1 only for a few exotic functionals.