Dear Stefano, do you think it is appropiate to use another functional to calculate the phonon spectra of molecular crystals? I just want to have some rough approximation of an IR spectrum and maybe get QHA total energies?
Thanks, Guntram Am 01.09.2011 12:37, schrieb Stefano de Gironcoli: > Dear Guntram, > be careful that vdW-DF functional IS NOT yet implemented in the > phonon code > Stefano > > On 09/01/2011 12:23 PM, Guntram Schmidt wrote: >> Dear All, >> >> I want to simulate the infrared spectrum of a molecular crystal. >> As the phonon calculations usually take weeks to finish, I'd like to >> ask, wether someone of you has propositions on proper treshold values? >> >> I'm using rpb-paw US pseudopotential (revised PBE, as suggested for >> vdW-potential) and gamma point (also said to be sufficient for molecular >> crystals). >> >> Does the ecutrho of the preceding SCF calculation influence the speed of >> the phonon calculation? >> >> What is a sufficient low value for the tr2_ph to get a reasonable >> (comparable to experimental values) spectrum? >> >> >> Thanks a lot, >> Guntram >> _______________________________________________ >> 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
