Imaginary frequencies are usually a sign of a mechanical instability, as discussed many times in this forum as well as in many condensed- matter textbooks. I think the answer is yours: if you want to calculate the electron-phonon interaction of an instable (possibly metastable) phase of a material, please do. If instead instability is soemething that troubles you, then you better settle your troubles first. Cheers - SB
On Dec 9, 2007, at 11:17 AM, Guoying Gao wrote: > Dear everyone, > I intend to do the electron-phonon coupling calculation. > However, I found some imaginary frequencies in the phonon band > structure. > So is it reasonable to calculate the lambda for the qpoints with > imaginary frequencies and why? > Thanks very much! > Guoying > National Lab of Superhard Materials, JiLin Univ, P. R. China > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum --- Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20071209/bd93d622/attachment.htm
