[Pw_forum] Imaginary phonon frequency

[Sonu Kumar]

Hi,

Follow this link...
http://www.quantum-espresso.org/?page_id=366#7.3

Also, are you sure that nq1 = 4, nq2 = 4, nq3 = 1  span your IBZ ?

with regards,

==========================================
Sonu Kumar
Phd Student, Physics Department
Indian Institute of Technology, Delhi-110016, India
mail: 1009ukumar at gmail.com
web:-http://www.iitd.ac.in/
==========================================


On Mon, Nov 12, 2012 at 5:17 AM, Caloma Trumica <spmmal at gmail.com> wrote:

> Dear All,
>
> I used nq1 = 4, nq2 = 4, nq3 = 1 to do a phonon calculation. The resulting
> inequivalent number of q points is 6.
>
> After a phonon calculation, all frequencies at these 6 points are real and
> reasonable.
>
> However, when I used these data to get a full phonon dispersion in the
> first BZ. I found that some q points have imaginary frequencies.
>
> Can someone tell me the possible reasons?
>
> Thank you.
>
> Andy
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20121112/4a6e2cec/attachment.html>