[Pw_forum] total energy for charged defects in semiconductors

[Paolo Giannozzi]

What I understood from the first paper you mention is that the recipe used
by QE is a good approximation to the correct term and it is fine for most
purposes.

P.

On Thu, Oct 22, 2015 at 10:18 PM, Mostafa Youssef <myoussef at mit.edu> wrote:

> Dear  Manhong,
>
> As far I know the incosistency of treating charged defects within PAW
> formalism discussed in  PHYSICAL REVIEW B 89, 045116 (2014) has not been
> resolved in any pseudopotential code. I  wish I can devote more time  to
> study this paper more carefully.
>
> Regarding the second paper,  PHYSICAL REVIEW B 91, 024107 (2015), it
> suggests that the arbitrariness  in the reference of the electrostatic
> potential has a sizable effect on the pressure (stress) calculated by DFT
> codes for charged systems.  Figure 1 tells the whole story.  The authors
> suggested a method to correct for that given the bulk modulus (eleastic
> constants) and the deformation potential. of the host semiconductor.
> However, the paper is of concern if you plan to do variable cell
> relaxation.  Most of the charged defects papers focus on fixed volume
> calculations claiming that this is a good way to represent dilute limit of
> defects.
>
> In summary, if you plan to do fixed volume calculations, the second paper
> should not be of concern  (roughly speaking).  Resolving the inconsistency
> of the first paper is to be implemented. To avoid it one might use all
> electron code.
>
>
> M. Y.
> MIT
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 
Paolo Giannozzi, Dept. Chemistry&Physics&Environment,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20151023/fbb8b497/attachment.html>