Thanks for the clarification! Florian
Am 07.11.2014 um 00:05 schrieb Paolo Giannozzi: > On Thu, 2014-11-06 at 13:32 -0800, Florian Altvater wrote: > >> just to clarify, do Grimme-D2 or the Tkatchenko-Scheffler correction >> fall under the "vdW of any kind" category > yes > >> or are they implemented in 5.1 for DFPT? > no. Any new develoment in the self-consistent code that contributes > an energy term has to be explicitly added to the DFPT calculation. > >> Also, I don't feel comfortable enough with the code yet to be able to >> find that information in the source, but I am sure it is in there >> somewhere. > in the header of the phonon.f90 code (although in a format whose logic > I never remember). Alternatively: if you know a key variable related > to some new development, and this variable is never used in the phonon > code, it is almost certain that the new development hasn't percolated > to the phonon code. > > Paolo > >> If you want to give me any pointers, so that I could >> potentially answer those questions myself in the future, I would greatly >> appreciate it. >> >> Thanks, >> Florian >> >> >> 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 >>>> _______________________________________________ >>>> Pw_forum mailing list >>>> [email protected] >>>> http://pwscf.org/mailman/listinfo/pw_forum >> --- >> Florian Altvater >> PhD candidate >> Neaton group >> 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
