[Pw_forum] Different optical mode frequency at the same q-vector

[Lorenzo Paulatto]

On 12 October 2012 01:14, Kyeong-hyun Park <kpark39 at gmail.com> wrote:

> To manage LO-TO splitting, I also set 'epsil=true'. That's pretty much what I have in my input files.
>
> I hope this is enough description to get a meaningful help. Any advice will be appreciated. Thank you.
>
>
I'm happy that you managed to write back.. I think your answer pretty much
solves the problem: if you use LO-TO splitting than the optical phonons
frequency at Gamma will depends on the direction. matdyn.x defines this
direction depending on the point that precedes Gamma in its list of
q-points.

If for some specific reason, you do not want the splitting to be computes,
you could open matdyn.f90 and hard-code lo_to_split to be .FALSE., or edit
the dynamical matrix file and remove the value Z*


-- 
Dr. Lorenzo Paulatto
IdR @ IMPMC -- CNRS & Université Paris 6
phone: +33 (0)1 44275 084 / skype: paulatz
www:   http://www-int.impmc.upmc.fr/~paulatto/
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