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 -- Paolo Giannozzi, Dept. Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222 _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
