[QE-users] Supercell relaxation

[VISHVA JEET ANAND]

Thank you for your answer.  When I put the atomic position in angstrom, I
got a crash report that is attached here.

On Mon, May 13, 2024 at 4:38 PM Giovanni Cantele <
giovanni.cantele at spin.cnr.it> wrote:

> Dear Vishva,
>
> before running any calculation it is a good practice to visualize your
> input structure, because many times convergence issues derive
> from errors in the input geometry.
>
> If you do so with yours, you see atoms at extremely small distances from
> each other, which prevents pw.x from reasonably converging
> in an acceptable number of steps.
>
> The second step is to understand why the structure is wrong. In your case
> my guess is that you tell pw.x that you're providing positions in alat
> units,
> whereas those units are Angstrom.
>
> The number of atoms depends on what you want to do. If you what to use a
> simple cubic unit cell (as in your input file) and the bcc unit cell is
> composed by N atoms,
> then the 1x1x1 CONVENTIONAL unit cell will contain 2N atoms. If, on top of
> that, you want also build a 2x2x2 unit cell, than that number has to be
> multiplied by 2x2x2.
>
> Giovanmi
> --
>
> Giovanni Cantele, PhD
> CNR-SPIN
> c/o Dipartimento di Fisica
> Universita' di Napoli "Federico II"
> Complesso Universitario M. S. Angelo - Ed. 6
> Via Cintia, I-80126, Napoli, Italy
> e-mail: giovanni.cantele at spin.cnr.it <giovanni.cantele at spin.cnr.it>
> Phone: +39 081 676910
> Skype contact: giocan74
>
> ResearcherID: http://www.researcherid.com/rid/A-1951-2009
> Web page: https://sites.google.com/view/giovanni-cantele/home
>
>
> Il giorno lun 13 mag 2024 alle ore 12:08 VISHVA JEET ANAND via users <
> users at lists.quantum-espresso.org> ha scritto:
>
>> Dear Users
>> I try to run Fe (bcc) structure 2x2x2 supercell for relaxation
>> calculation but scf does not converge in 1000 iterations. Secondally how
>> many no. of atoms in Fe (bcc) structure. Here I attached my input file.
>>
>> --
>> With Regards
>> Vishva Jeet Anand
>> Research Scholar
>> Department of Chemistry
>>
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>

-- 
With Regards
Vishva Jeet Anand
Research Scholar
Department of Chemistry
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