[QE-users] Symmetry identification difference between QE versions

[KRISHNENDU MUKHERJEE]

 Thank you Paolo for your kind reply and discussion. I would also thank Shimin Zhang for putting up the question so nicely. I also had those questions for some time.

----- Original Message -----
From: "paolo giannozzi" <paolo.giannozzi at uniud.it>
To: users at lists.quantum-espresso.org
Cc: "KRISHNENDU MUKHERJEE" <krishnendu at nmlindia.org>
Sent: Sunday, February 12, 2023 11:29:57 PM
Subject: Re: [QE-users] Symmetry identification difference between QE versions

On 12/02/2023 14:08, KRISHNENDU MUKHERJEE wrote:

> If some of the symmetry operators are missed, may be the shape and the 
> size of the Brillouin Zone can change. 

only if you perform structural optimization, and if your system does not 
like the initial symmetry

Paolo

> Can that have an effect on the scf energy calculation?
> 
> Thank you,
> Regards,
> Krishnendu
> 
> 
> On 11/02/2023 00:17, Shimin Zhang via users wrote:
> 
>  > My question is what could be the factor to cause this arbitrary symmetry
>  > identification?
> 
> small numerical differences between the true symmetric coordinates and
> axis and the almost symmetrical ones you have
> 
>  > What is the difference between these two versions of QE in the sense of
>  > identifying the symmetry?
> 
> nothing important, but it is hard to say more: much may have happened in
> the almost 4 years since v.6.4 was released
> 
>  > What is the consequence if some symmetry operators are missed?
> 
> more k-points used
> 
>  > Can I input the symmetry myself?
> 
> yes, with space groups and Wyckoff positions, but for a supercell it may
> be annoying
> 
> Paolo
> 
>  > Best,
>  > Shimin Zhang
>  > PhD student  in University of California, Santa Cruz
>  >
> 
> 
> 
> 
> 
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-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 206, 33100 Udine Italy, +39-0432-558216