[Pw_forum] Phonons of molecular crystal

[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