Dear Vikas, One simplest thing you can do is to read the DFT-D2 part of DFT-D3 code provided by Grimme's group (http://toc.uni-muenster.de/DFTD3/) You will be able to find all necessary coefficients for all atoms with Z<=86. Then you have to add them to mm_dispersion.f90. Recompile QE, then you are good to go. -------------------------------------------------- Duy Le PhD Candidate Department of Physics University of Central Florida.
"Men don't need hand to do things" On Tue, Jun 21, 2011 at 10:40 AM, Vikas Varshney <vv0210 at gmail.com> wrote: > Dear All, > > I am trying to relax my WS2 unit cell structure using vc-relax (using PBE > pps) and I want to include disperson corrections to it. So, I tried using > the london flag = .true. However, on starting my job I got an error > > ?%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > ???? from? init_london? : error #???????? 1 > ???? atom W?? not found > ?%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > > After going through mm_dispersion.f90, I found that the vdw_radius and c_6 > parameters are given for first 54 atoms only (which corresponds to first 5 > periods of periodic table). Tungsten (W), with atomic number of 74 is in 6th > period. > > I emailed Prof. Stefan Grimme (author of the references that are mentioned > in mm_dispersion.f90) if anything was further pursued. He replied mentioning > that they have approached this problem further and referred me to his > website, > > http://toc.uni-muenster.de/DFTD3/ > > and told me that this has already been implemented into major QM codes. > > Mentioning that, I have few questions. > 1. I wanted to ask if QE has incorporated the additions DFT-D, recently. > 2. Are there any other ways to incorporate dispersion interactions in > calculations in DFT. > > Currently, I am running my simulations on 4.2 version of the code that I > downloaded few months ago. I would high appreciate your insights in how > should I go about solving this problem regarding dispersion interactions in > Tungsten. > > Looking forward for a positive reply. > > Best Regards, > > Vikas Varshney, > Computational Materials Scientist, > Wright-Patterson Air Force Base, Dayton-OH (USA). > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > >
