Thanks so much Prof. Giannozzi. I apologize for repeating the question. Sridhar
On Wed, May 28, 2014 at 1:31 AM, Paolo Giannozzi <paolo.giannozzi at uniud.it>wrote: > I just added point 7.7 of the FAQs, since this question is asked > more often than not: http://www.quantum-espresso.org/faq/phonons/#7.7 > > P. > > On Tue, 2014-05-27 at 09:20 +0530, Sridhar Sadasivam wrote: > > Dear QE users and developers, > > > > > > I am trying to use the real space force constants file obtained from > > q2r.x to do some other calculations outside of QE. For this purpose, I > > am trying to understand the format of the force constants file. I am > > attaching a sample force constants file obtained by performing ph.x > > and q2r.x on bulk silicon with a 4 x 4 x 4 q-mesh. > > > > > > In the 22nd line in the file, it says 1 1 1 1. I believe the first two > > 1's denote the x-direction and the last two 1's denote atom numbers > > within the two-atom unit cell of silicon. After this it loops over all > > 64 different combinations of indices in a 4 x 4 x 4 mesh and lists the > > force constants in the 4th column. What do these 64 different > > combinations mean? Do they denote unit cells? > > > > > > For instance, let's take the first line: 1 1 1 2.6997. 2.6997 is the > > force constant between which atoms? > > > > > > Thanks for your help! > > Sridhar > > Purdue University > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://pwscf.org/mailman/listinfo/pw_forum > > > _______________________________________________ > 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/20140528/e176df7a/attachment.html