Hi, Stefano: Many thanks for the literature you brought up. That's what I'm looking for.
Best, Wei On Fri, Oct 3, 2008 at 3:00 AM, Stefano de Gironcoli <degironc at sissa.it>wrote: > > I don't know the details of the generation of this particular PP but in > the old good times there has been a very detailed comparison of LDA band > structure calculation of Ge and GaAs between the PP method and LMTO [GB > Bachelet and NE Christensen, Phys.Rev.B 31, 879 (1985) ]. > The main result is that in order to get the correct (bad) gap in Ge and > GaAs 1) scalar relativistic, 2) spin-orbit coupling, 3) 3d-state > relaxation > are important... not to mention convergence w.r.t. to cutoff ... > > Hope this helps, > > Stefano de Gironcoli - SISSA and DEMOCRITOS > > willy kohn wrote: > > 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 <mailto: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 <mailto: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 > > <mailto: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 > > <mailto: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. > > > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > 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 > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20081004/a6f1c1b0/attachment.htm
