R2SCAN D4 parameters not automatically selected

[asrosen]

The DFT-D4 section of the wiki (https://www.vasp.at/wiki/DFT-D4) states:

Internally, VASP passes the name of the used exchange-correlation functional to DFT-D4. Subsequently, DFT-D4 maps this name of the functional to optimized settings for the adjustable parameters of the vdW interaction.

I have compiled VASP 6.5.1 with DFT-D4 3.7.0 support, which I believe supports r2SCAN parameters out-of-the-box (https://github.com/dftd4/dftd4/blob/2a8 ... .toml#L363). However, when running with IVDW = 13 and METAGGA = r2scan, I get back an internal VASP error that this an unsupported xc functional. This suggests to me that VASP not passing on the name of the functional correctly to the D4 executable.

Of course, the solution is simple: specify the parameters manually. However, I am reporting this in case there is indeed some name passing issue.

[ferenc_karsai]

I have tested the problem myself and can reproduce it.
The problem occurs because "r2scan" is not recognized as known functional in (VERBALIZE_DFTMETHOD in mymath.F).
"scan" for example is and the code can automatically set the default parameters for it.
There are more functionals missing in that list and we will have to make the list in that file. It's on our to-do list.

Thank you very much for bringing the problem to our attention.

[asrosen]

Glad to help. Thanks again for the reply!

If there is any interest in updating the available D3 parameters, I'm sure there would be interest from users as well :) https://github.com/dftd3/simple-dftd3/b ... eters.toml