QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: quantumtoday on April 3, 2017, 10:46

Title: Choosing approriate pseudopoptentials
Post by: quantumtoday on April 3, 2017, 10:46

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?



 

Title: Re: Choosing approriate pseudopoptentials
Post by: Jess Wellendorff on April 3, 2017, 14:48

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

Title: Re: Choosing approriate pseudopoptentials
Post by: quantumtoday on April 3, 2017, 16:02

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.

Title: Re: Choosing approriate pseudopoptentials
Post by: Jess Wellendorff on April 4, 2017, 08:57

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.