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EPW phonon bandstructure inconsistent with QE results

Posted: Tue Feb 23, 2021 9:40 am
by Qiaolin
Dear all,

Recently, I try to use EPW to study transport property. The phonon dispersion with SOC agrees with the QE results, but the LO and TO frequency of G point is still denegrated. I have set " lpoar = .true. lifc = .true. asr_typ = 'crystal' "

Image

Is this a normal phenomenon? I put my input in the following:
https://github.com/Isabellelin/g_matric ... ain/SiC_ph

Thanks in advance if anyone can help the problem.

Sincerely,
Qiaolin

Re: EPW phonon bandstructure inconsistent with QE results

Posted: Tue Feb 23, 2021 4:51 pm
by hlee
Dear Qiaolin:

Which version of EPW are you using?
In addition, could you provide me with the file of LGXKG_50.txt ?

Sincerely,

H. Lee

Re: EPW phonon bandstructure inconsistent with QE results

Posted: Wed Feb 24, 2021 2:28 am
by Qiaolin
Hi Mr. Lee,

The version of QE and EPW I used are 6.7 and 5.3.1.
LGXKG_50.txt : https://github.com/Isabellelin/g_matric ... XKG_50.txt

Best Regards,
Qiaolin

Re: EPW phonon bandstructure inconsistent with QE results

Posted: Thu Feb 25, 2021 8:26 pm
by hlee
Dear Qiaolin:

I think that this difference can't be avoided since EPW doesn't include the non-analytic term which results in the LO-TO splitting in SiC.
For example, if you add to matdyn.in "loto_disable = .true." (with loto_disable set to true, the non-analytic term is not included in matdyn.x, even the result from matdyn.x doesn't show the LO-TO splitting at q=0 in SiC by skipping the call to the subroutine of nonanal. Please see https://gitlab.com/QEF/q-e/-/blob/devel ... n.f90#L618 .

Sincerely,

H. Lee