VDW_C6 Tag Value for Pt in PBE+D2 Correction

[nidhi_tiwari]

In the context of PBE+D2 correction with IVDW set to 1, I want to know the VDW_C6 tag value for Pt. The default value in OUTCAR is 81.240 when only IVDW is specified in INCAR. However, in a literature, VDW_C6 was stated to be 24.670 for Pt. Which of these values is considered correct in this scenario?

[fabien_tran1]

According to the original DFT-D2 code written by Grimme and collaborators (https://www.chemiebn.uni-bonn.de/pctc/m ... /dftd3.tgz), the value VDW_C6=81.24 is for Ta-Au, while VDW_C6=24.67 is for Rb-Cd.

[nidhi_tiwari]

Thank you for providing clarification. I appreciate your assistance. Nevertheless, I was unable to locate information regarding the Ta-Au elements in the reference https://onlinelibrary.wiley.com/doi/10.1002/jcc.20495.

[fabien_tran1]

There is indeed no values for Ta-Au in the original DFT-D2 paper. Either the values were published in a subsequent paper or the authors did not consider it worth to write a paper for that. Anyway, DFT-D2 is somehow considered as obsolete, so that the recommendation would be to use the more recent DFT-D3 or DFT-D4 methods. The nonlocal van der Waals functionals (https://www.vasp.at/wiki/index.php/Nonl ... unctionals) can also be considered as good alternatives.