[QE-users] Does order of atoms matter in Quantum Espresso?

[Paolo Giannozzi]

On Mon, Dec 30, 2019 at 11:08 PM Sheikh Ziauddin Ahmed <sza9wz at virginia.edu>
wrote:

I am trying to calculate the phonon dispersion of AlSb. I am getting two
> different results depending on how I am introducing the atoms in the SCF
> calculation. Will the order of the atom change the symmetry of the zinc
> blende AlSb?
>

no. See attached.

PG


> In the first case the input deck is:
> &system
>     ibrav=2, nat=2, ntyp=2,
>     ecutwfc = 50, ecutrho = 500,
>     occupations='smearing',
>     smearing='gauss',
>     degauss=0.05,
>     celldm(1)=11.5944146,
>  /
>  &electrons
>     conv_thr    = 1.0e-12
>     mixing_beta = 0.7
>     mixing_mode = 'local-TF'
>  /
> ATOMIC_SPECIES
>  Al 26.98 al_lda_v1.uspp.F.UPF
>  Sb 121.76 sb_lda_v1.4.uspp.F.UPF
> ATOMIC_POSITIONS (alat)
>  Al 0.0   0.0   0.0
>  Sb 0.25  0.25  0.25
> K_POINTS automatic
> 6 6 6 0 0 0
>
> In the second case the input deck is:
>  &system
>     ibrav=2, nat=2, ntyp=2,
>     ecutwfc = 50, ecutrho = 500,
>     !occupations='smearing',
>     !smearing='gauss',
>     !degauss=0.05,
>     celldm(1)=11.5944146,
>  /
>  &electrons
>     conv_thr    = 1.0e-12
>     mixing_beta = 0.7
>     mixing_mode = 'local-TF'
>  /
> ATOMIC_SPECIES
>  Sb 121.76 sb_lda_v1.4.uspp.F.UPF
>  Al 26.98 al_lda_v1.uspp.F.UPF
> ATOMIC_POSITIONS (alat)
>  Sb 0.0   0.0   0.0
>  Al 0.25  0.25  0.25
> K_POINTS automatic
> 6 6 6 0 0 0
>
> Thanks in advance!
> --
> *Sheikh Ziauddin Ahmed *
> PhD Candidate
> Charles L. Brown Department of Electrical and Computer Engineering
> University of Virginia
> Email:sza9wz*@virginia.edu* <sza9wz at virginia.edu>
> LinkedIn: https://www.linkedin.com/in/sheikh-ziauddin-ahmed
> _______________________________________________
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso)
> users mailing list users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users



-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
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/20200102/7c4320c1/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: AlSb.tar.gz
Type: application/x-gzip
Size: 22198 bytes
Desc: not available
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20200102/7c4320c1/attachment.bin>