rrkjus refers to an US pseudopotential geerated in two steps. first a hard NCPP is generated according to the rrkj recipe and then an USPP is generated whose augmentation charges reproduce the one of the previous NCPP.
stefano On 01/31/2011 01:31 PM, Davide Sangalli wrote: > Thanks for the answers to question 1. > So rrkjus from quantum espresso are not norm conserving (indeed I'm using > rrkjus > psps). > > I supposed that rrkj means a pseudo created according to the rrkj scheme > presented in PRB 41, 1227 (1990). > In that paper the proposed psps are norm-conserving. Is that correct? > Is there any another paper I should look for? > > Regards, > Davide > > On 01/31/2011 12:41 PM, Davide Sangalli wrote: > > Dear forum, > > I'm doing calculations with rrkj pseudo-potentials. > > > > As far as I understand rrkj are norm-conserving psps and only ecut should > > be > > checked, while ecutrho=4*ecut should be fine. > > From this I guess that the ecutrho paramater, if increased, should not > > influence the convergence. > > > > I did some test and I saw that this is not true. Increasing ecutrho (at > > fixed > > ecut) the results changes significantly. For example the elements of the > > stress tensor changes more than 15 Kbar (in some case even more) moving > > ecutrho from 140 to 300 Ry (with ecut=35 Ry). Here I was testing FeO, CoO > > and > > NiO, with pbe/rrkj psps for all thee elements. > > *Question 1: Why ? > > *(I saw that in the psps header Rcut and Rcut US are different ... ?) > > > > I did these checks even because I would like to perform calculations using > > vanderbilt psp (for some elements) together with rrkj psp (for other > > element?). > > *Question 2: Is there any counter indication in doing that ? > > * > > Thanks and best regards, > > Davide Sangalli > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110131/9c9566c7/attachment.htm
