Choosing approriate pseudopoptentials

[quantumtoday]

Hi all,
In case we have an overlap structure with the middle part made of bilayer structure, and the others made of single layer structure, for instance:
(top layer)            -------------------------------------------

(bottom layer)                                             ------------------------------------------
How should we choose pseudopotentials for DFT calculations?  simply choosing pseudopotentials with GGA, LDA or it should be vdw or even both?



 

[Jess Wellendorff]

You should probably choose a GGA exchange-correlation, possibly with vdW semi-empirical (Grimme type) corrections, and therefore also a GGA pseudopotential.

[quantumtoday]

Thank you, Jess Wellendorff.

I am trying to guess a general and an appropriate choice of pseudopotential for this problem, not only with ATK but also with other codes such as Siesta or QE.

[Jess Wellendorff]

The completely general solution would be to go with pseudopotentials that match the exchange-correlation functional you use, e.g. a GGA potential if using GGA exchange-correlation (w/wo vdW), and a LDA potential is using LDA. Same story in all DFT codes.