Dear M Lahmer the DFT+U implementation in PWscf is the one described in Phys Rev B 71, 035105 (2005) by M. Cococcioni and S de Gironcoli. The U parameter defined in PWscf is directly the U_eff = U-J you are referring to and the alpha parameters are used to perturb the system away from its LDA minimum, or other reference systems that might be more convenient [see PRL 97, 103001 (2006) by Kulik, Cococcioni, Scherlis and Marzari], to calculate the U parameter from first principles following the recipe given in that paper.
hope this helps, best regards, stefano de Gironcoli - SISSA and DEMOCRITOS patriot pershing wrote: > M Lahmer > Laboratory of physics and chemistry of semiconductors > university of constantine > > 2010/3/17, Stefano de Gironcoli <degironc at sissa.it>: > >> dear patriot >> please provide your identity and affilaition >> best regards, >> Stefano de Gironcoli - SISSA nd DEMOCRITOS >> >> patriot pershing wrote: >> >>> dear please: >>> i would do LDA+U calculation on ZnS and ZnO material using Quantum >>> Espresso code and i would use Ueff in my calculations which is defined >>> as U - J by changing these 2 parameters but when i have traied to do >>> this using espresso code i don't arrived to do this because only the U >>> value as well as alpha parameter can be modified for this reason i >>> would if any one can help me in this point. secondly, i would ask what >>> i need to do GGA+U calculations? ( i think in espresso is just do >>> LDA+U calculation + USPP with GGA exchange-correlation function) >>> best regards >>> _______________________________________________ >>> Pw_forum mailing list >>> Pw_forum at pwscf.org >>> http://www.democritos.it/mailman/listinfo/pw_forum >>> >>> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum >
