Dear Giuseppe, is there any concrete evidence that "ab initio" van der Waals vdW-DF is systematically better than Grimme's vdW? Are you aware of any paper comparing the latest version of the two methodologies (or "phisolophies", if you want), i.e. vdW-DF2 vs DFT-D3?
Cheers, GS Il giorno 23/mar/2011, alle ore 10.12, giuseppe.mattioli at mlib.ism.cnr.it ha scritto: > > Dear all > You can do better than the semiempirical "Grimme" correction. There is > a new ab initio van der Waals correlation functional implemented in QE > 4.3a. Try input_dft='vdW-DF', in the &sysytem list. > By the way, what about a (semiempirical or ab initio) vdW scheme in > cp.x? Is there any project going on? > > Yours > > Giuseppe > > Quoting Masoud Nahali <masoudnahali at gmail.com>: > >> Dear Eric >> >> Try london="true" to get improved answer; as you should know DFT is weak >> to calculate dispersion forces and by using the keyword one can include >> these forces semi-empirically. I hope it helps. >> >> Best Wishes >> >> Masoud >> -------------- >> Masoud Nahali, Sharif University of Technology >> >> >> Eric Wrote: >> >> Dear all, >> >> I'm trying to optimize unit cell parameter of graphite. >> The problem is the c axis gets too long. >> Starting from published data my initial parameters are a=4.59203 Bohr >> and c=12.513 Bohr. >> The final values are 4.664 and 15.829 respectively. >> I need someone to explain to me what I did wrong, I've attached my input >> file. >> That's a basic calculation so it's very frustrating to not make it done. >> I thank you in advance, >> >> Eric. >> >> -- >> /Be the change you wish to see in the world >> / --- Mahatma Gandhi --- >> >> Dr. ?ric Germaneau <mailto:germaneau at gucas.ac.cn >> <http://www.democritos.it/mailman/listinfo/pw_forum>> >> >> College of Physical Sciences >> Graduate University of Chinese Academy of Sciences >> Yuquan Road 19A >> Beijing 100049 >> China >> > > Giuseppe Mattioli > ISM-CNR > Italy > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum ? Gabriele Sclauzero, EPFL SB ITP CSEA PH H2 462, Station 3, CH-1015 Lausanne -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110323/7938c063/attachment.htm
