[Pw_forum] How to get the usual ~2.4 eV band gap of ZnO with HSE06?

[Tan Hengxin]

Dear Nicola,

All the pseudopotentials are come from the pslibrary.0.3.1.
The ones that give ~2.1 eV are pz-lda, and the ones that give ~1.8 eV are
pbe.
In my calculations, the ecutoff is just 60 Ry.

Your suggestions are great. I will try pseudopotentials from SG15_oncv to
see if I can get what I want.

Thank you.
Regards,
Hengxin

On Fri, Aug 11, 2017 at 10:11 PM, Nicola Marzari <nicola.marzari at epfl.ch>
wrote:

> On 11/08/2017 15:10, Tan Hengxin wrote:
>
>>         My value is just ~2.1 eV.
>>         Maybe my norm-conserving pseudopotentials (NC-PPs) of Zn and O
>>         are not very good. So I also tried the NC-PPs for Zn and O from
>>         the pslibrary.0.3.1. However, the gap is even smaller (~1.8 eV).
>>         (All PPs are based on PBE xc.)
>>
>
>
> This already tells you that the pseudopotentials are certainly a problem.
> You might have also other problems, of course - but these are one. Where do
> the original ones come from? (the ones that give you 2.1)?
>
> After having seen the SSSP tests I would try the Zn and O from SG15, at
> ~100 Ry: http://www.quantum-simulation.org/potentials/sg15_oncv/
>
> Can you report what you get?
>
> Thanks,
>
>                         nicola
>
> --
> ----------------------------------------------------------------------
> Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL
> Director, National Centre for Competence in Research NCCR MARVEL, EPFL
> http://theossrv1.epfl.ch/Main/Contact http://nccr-marvel.ch/en/project
>



-- 

Tan Hengxin
Department of physics, THU.
Beijing 100084, China
Office: B403,New Science Building
E-mail:t <E-mail%3Athx13 at mails.tsinghua.edu.cn>anhx90 at gmail.com
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