[QE-users] [EXT] Total energy of charged slabs

[nisidate nisidate]

> 2021/08/17 8:51、Andreussi, Oliviero <Oliviero.Andreussi at unt.edu>のメール:
> 
> Standard DFT (e.g. PBE) suffers from self-interaction errors, among other approximations. As a 

Yes, but one of the other ways to handle charged system is to use 
the ESM method.

M. Otani and O. Sugino, "First-principles calculations of charged
surfaces and interfaces: A plane-wave nonrepeated slab approach," PRB
73, 115407 (2006).

It has been implemented in the QE; see the files in the directory:
 qe-6.8/PW/examples/ESM_example

It seems me works fine for my charged fuel cell slab system :).

> Besides, another related question is how we define the zero energy in
> QE?

Energy zero is defined arbitrarily in the DFT calculation. I usually
tried to estimate the energy standard rather than the energy zero to
be the potential energy of vacuum in the slab system.

You can estimate it by plotting the x-y averaged potential energies
along the z-direction. This function is also implemented in the ESM
calculation (check the *.esm file in the work directory).


best regards
kazume NISHIDATE
敬具　西館数芽

nisidate at iwate-u.ac.jp
kazume.nishidate at gmail.com