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://pwscf.org/pipermail/pw_forum/attachments/20121112/4a6e2cec/attachment.html
