I'm going to perform a set of calculation using PBE functional for modified MoS2: a layered compound with layers bound by vdW forces. Since I need to estimate interlayer distances with at least 0.5A precision, I need to explicitly account vdW forces, since vanilla PBE grossly overestimates equilibrium interlayer distance.
However, pw_input is very vague on specifying custom function, sending to Modules/func.f90, and the file mentions functionals implemented and specifies components for shorthands, but does not provide a clear example. example jobs show setups for provided vdW functionals, but not custom ones. However, I have a large set of previous calculations with rel-PBE used, and I'm not excited by perspective to re-run them for comparison needs. So, the questions are: 1) How to specify a custom functional for rel-PBE pseudopotentials with vdW correction added? 2) How much difference I should expect for energy of hydrogen dissociation energy when I add vdW?
_______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
