It is impossible to answer on the basis of so little information. It is difficult even in presence of all needed information, since complete phonon dispersions take so long to complete.
Reminder: under some circumstances, phonons in v.5.0.2 may turn out to be incorrect. Use patched version 5.0.3. P. On Mon, 2013-11-18 at 09:44 +0900, Myungchul Jung wrote: > Hi users, > > In ABO3 structure, I consider an Osomate system. > I used a PBE-pseudopotential. > ecut = 40 Ry, ecutrho=400 Ry. > First I used k-mesh 14*14*14 and q-mesh 2*2*2, then I got the > imaginary freq. > So, I used k-mesh 20*20*20 and q-mesh 2*2*2, then I didn't get the > freq. > But, when I used 4*4*4 q-mesh, I got a imaginary freq again. > How I do to solve this problem? > > Sincerely, > Myung-Chul. > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum -- Paolo Giannozzi, Dept. Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222
