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 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20121111/3db056b4/attachment.html
