Hi Paolo, thanks for the info. A check would definitely be helpful as long as it is not implemented.
Thanks, Flo Am 05.11.2014 um 11:06 schrieb Paolo Giannozzi: > On Wed, 2014-11-05 at 03:51 -0800, Florian Altvater wrote: >> Hi, >> I am interested in looking at effects of using van der Waals functionals >> like vdW-DF2 on the phonon dispersion of organic crystals. Preliminary >> results indicate that there might be some issues with using DFPT and DF2 >> together. More specifically, DFPT gives a couple "very imaginary" >> frequencies (below -100cm^-1) for Gamma-point phonons (with and without >> acoustic sum rule), while finite displacement results seem to be just >> fine, using the same convergence parameters. >> >> So before I dig deeper into eventual other issues at play here, I wanted >> to ask if you know of any incompatibilities when using DFPT and vdW-DF2? > DFPT + vdW (any kind) is not currently implemented. The next version > (out in a few days) will contain a check on this > > Paolo > >> Either inherently embedded in the underlying theory (which I could then >> dig into first), or just in the way it is implemented in QE. >> >> Thanks for your help, >> Florian >> >> --- >> Florian Altvater >> PhD candidate >> UC Berkeley/LBNL >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
