The kinetic-energy cutoff is a property of the atomic core, NOT of the specific system (to a large extent). SB
On May 10, 2008, at 6:11 PM, Roberto G. A. Veiga wrote: > Dear Stefano: > > I'm using Ultrasoft PPs. My question was because this cutoff (20 Ry) > seemed to be appropriate for other carbonic systems. > > []s, > > Roberto > > Stefano Baroni <baroni at sissa.it> wrote: > > On May 9, 2008, at 10:42 PM, Roberto G. A. Veiga wrote: > >> Hi, Konstantin: >> >> thank you very much. Such a large cutoff (80 Ry) is necessary for >> convergence? Or maybe I'm using one quite small (20 Ry)... > > it depends on the PP you are using, I guess, and certainly NOT on > the actual structure you are studying. 80 Ry seems like an > appropriate cutoff for moderately hard norm-conserving PP's, whereas > 20 Ry sounds like appriate for many US PP's. In either case, you > better check the aprporiateness by yourself, through thorough > convergence tests. > > Stefano > > >> >> >> []s, >> >> Roberto >> >> Konstantin Kudin <konstantin_kudin at yahoo.com> wrote: >> Hi Roberto, >> >> Here is a ribbon input that works for sure: >> https://kiev.princeton.edu/misc/rg_07.scf.in >> (get PPs from the PWSCF website) >> >> Good luck! >> Kostya > > --- > Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - > Trieste > [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) > > La morale est une logique de l'action comme la logique est une > morale de la pens?e - Jean Piaget > > Please, if possible, don't send me MS Word or PowerPoint attachments > Why? See: http://www.gnu.org/philosophy/no-word-attachments.html > > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > > Be a better friend, newshound, and know-it-all with Yahoo! Mobile. > Try it now._______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum --- Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) La morale est une logique de l'action comme la logique est une morale de la pens?e - Jean Piaget Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20080511/2d391ac5/attachment.htm
