Hi, Axel: Well, I didn't blame the PP, and I didn't mean to. My question is quite simple. I was told that with a LDA PP, Ge has a vanishing or negative band gap at Gamma point. But with this PP, it has a gap of 0.50 eV (using experimental lattice) or 0.80 eV (after relaxation). I'm not sure what I knew is correct, and that is the reason I wanted another PP to verify.
Best, Wei On Thu, Oct 2, 2008 at 2:12 PM, Axel Kohlmeyer <akohlmey at cmm.chem.upenn.edu>wrote: > On Thu, 2 Oct 2008, willy kohn wrote: > > WK> Hi, Axel: > WK> > WK> Thanks a lot for your quick answer. I need to do some calculations on > some > WK> compound semiconductors of Ge. But the PP (Ge.pz-bhs.UPF) provided in > the > WK> PWSCF website yeided some results that I don't understand. So I would > like > > perhaps it would be useful to explain in more detail what > is confusing you and what calculation you did with what input. > perhaps some people here can comment on it. it is always easy > to blame the pseudopotential (sometimes rightfully so), but > more often than not, the real cause is in not doing a calculation > correctly, or not using a pseudopotential correct. > > WK> to use some other PP's to check if I did the calculation correctly. Any > WK> suggestions? > > i have a set of Ge pseudopotentials generated from parameters > for a norm-conserving troullier-martins potential that is in > the extended CPMD psp library. they have seen only very minimal > transferability testing (using an atomic code in bessel basis), > but so far seem to be ok, except for the OLYP one which has a > ghost in the s-channel. > > i can send them to you in a private mail, if you are interested. > no guarantees etc... > > cheers, > axel. > > WK> > WK> Best, > WK> > WK> Wei > WK> > WK> On Thu, Oct 2, 2008 at 11:54 AM, Axel Kohlmeyer < > akohlmey at cmm.chem.upenn.edu > WK> > wrote: > WK> > WK> > On Thu, 2 Oct 2008, willy kohn wrote: > WK> > > WK> > WK> Dear PWSCF users: > WK> > WK> > WK> > WK> I have a quick question about using > WK> > WK> Hartwigsen-Goedeker-Hutter< > WK> > > http://cvs.berlios.de/cgi-bin/viewcvs.cgi/cp2k/potentials/Goedecker/abinit/pade > WK> > >pseudopotential > WK> > WK> with PWSCF. Is there any converter to transfer the HGH pp > WK> > WK> format to UPF used in PWSCF? > WK> > > WK> > none that i am aware of. > WK> > > WK> > the GTH pseudopotentials are analytical in real and reciprocal > WK> > space and to incorporate them properly, one would have to do a > WK> > lot of programming. in the CPMD code (from http://www.cpmd.org) > WK> > they are treated as a special case, similar to ultra-soft psps. > WK> > > WK> > is there any particularly reason you'd need any of those? > WK> > > WK> > cheers, > WK> > axel. > WK> > > WK> > > WK> > WK> > WK> > WK> Best, > WK> > WK> > WK> > WK> Wei > WK> > WK> > WK> > WK> Georgia Tech > WK> > WK> > WK> > > WK> > -- > WK> > > ======================================================================= > WK> > Axel Kohlmeyer akohlmey at cmm.chem.upenn.edu > http://www.cmm.upenn.edu > WK> > Center for Molecular Modeling -- University of Pennsylvania > WK> > Department of Chemistry, 231 S.34th Street, Philadelphia, PA > 19104-6323 > WK> > tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel: > 1-215-898-5425 > WK> > > ======================================================================= > WK> > If you make something idiot-proof, the universe creates a better > idiot. > WK> > > WK> > > -- > ======================================================================= > Axel Kohlmeyer akohlmey at cmm.chem.upenn.edu http://www.cmm.upenn.edu > Center for Molecular Modeling -- University of Pennsylvania > Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323 > tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel: 1-215-898-5425 > ======================================================================= > If you make something idiot-proof, the universe creates a better idiot. > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20081002/960c885d/attachment-0001.htm
