Dear Gabrielle and Lorenzo, Thanks very much for the links. I will be having a look at them.
Regards Elie From: [email protected] Subject: Re: [Pw_forum] phonon calculations in a spercell of 100 atoms Date: Mon, 13 Feb 2012 17:41:13 +0100 To: elie.moujaes at hotmail.co.uk Dear Elie, you might want to have a look at Dario Alf?'s webpagehttp://www.homepages.ucl.ac.uk/~ucfbdxa/phon/He has a code that should do what you need. HTH GS Il giorno 13/feb/2012, alle ore 17.24, Elie M ha scritto:Thanks for your reply. Any reference to the finite displacement method for phonon calculations using QE? Thanks again Elie > To: pw_forum at pwscf.org > Date: Mon, 13 Feb 2012 16:41:04 +0100 > From: Lorenzo.Paulatto at impmc.upmc.fr > Subject: Re: [Pw_forum] phonon calculations in a spercell of 100 atoms > > On Mon, 13 Feb 2012 16:36:55 +0100, Elie M <elie.moujaes at hotmail.co.uk> > wrote: > > Dear all, > > I have two questions: > > (1) I am running phonon calculations on a system of 100 atoms and only > > at the Gamma point! It is really taking a lot of time. It is running in > > the parallel computing mode with a total of 16 processors on 2 nodes and > > still is going slow. Is there a way to speed up things? and is there a > > way to do the whole phonon dispersion in lesser time? > > Do not use a supercell? Seriously, phonon calculations are expensive, with > many atoms they are extremely expensive. If you only need the phonons at > the gamma point, it may be faster to get them by finite displacement, > doing 3*nat pw.x ground state calculations. > > > (2) If only the phonon frequencies at the Gamma point were calculated , > > I was wondering what kind of information about the system can one get? > > Thanks > > If the supercell is large enough, all the information you need. > > bests > > > -- > Lorenzo Paulatto IdR @ IMPMC/CNRS & Universit? Paris 6 > phone: +33 (0)1 44275 084 begin_of_the_skype_highlighting +33 (0)1 > 44275 084 end_of_the_skype_highlighting / skype: paulatz > www: http://www-int.impmc.upmc.fr/~paulatto/ > mail: 23-24/4?16 Bo?te courrier 115, 4 place Jussieu 75252 Paris C?dex 05 > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum ? Gabriele Sclauzero, EPFL SB ITP CSEA PH H2 462, Station 3, CH-1015 Lausanne -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120213/f37b5ed1/attachment-0001.htm
