Dear Sonu, Of course, there is no cutoff energy in phonon input file. But the second order derivatives to define phonons are related to the charge density and its first order derivative. So, phonons are dependent on the cutoff energy. In its turn, the cutoff energy is connected to a Pseudo-type used.
Yes, I meant tr2_ph parameter. Bests, Eyvaz. ------------------------------------------------------------------- Prof. Eyvaz Isaev, Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com ________________________________ From: sonu kumar <[email protected]> To: pw_forum at pwscf.org Sent: Sat, July 31, 2010 7:41:07 AM Subject: Re: [Pw_forum] Fourier interpolation Dear Prof. Eyvaz Isaev and QE users, > Play around cutoff energy and the threshold parameter for phonons. where is the cutoff energy parameter related to phonon calculations? i couldn't find it in the manual for ph.x. Only "tr2_ph" theshold parameter is there in addition to "eth_rps" and "eth_ns" parameters for Raman calculations. i am sorry if am wrong. Thank you very much. With Kind Regards, Sonu Kumar Phd Student Physics Department IIT Delhi -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100731/c65b5d68/attachment.htm
