<div dir="ltr">Hi, Stefano:<div><br></div><div>Many thanks for the literature you brought up. That's what I'm looking for. </div><div><br></div><div>Best,</div><div><br></div><div>Wei</div><div><br><br><div class="gmail_quote">
On Fri, Oct 3, 2008 at 3:00 AM, Stefano de Gironcoli <span dir="ltr"><<a href="mailto:degironc@sissa.it">degironc@sissa.it</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<br>
I don't know the details of the generation of this particular PP but in<br>
the old good times there has been a very detailed comparison of LDA band<br>
structure calculation of Ge and GaAs between the PP method and LMTO [GB<br>
Bachelet and NE Christensen, Phys.Rev.B 31, 879 (1985) ].<br>
The main result is that in order to get the correct (bad) gap in Ge and<br>
GaAs 1) scalar relativistic, 2) spin-orbit coupling, 3) 3d-state relaxation<br>
are important... not to mention convergence w.r.t. to cutoff ...<br>
<br>
Hope this helps,<br>
<br>
Stefano de Gironcoli - SISSA and DEMOCRITOS<br>
<div class="Ih2E3d"><br>
willy kohn wrote:<br>
> Hi, Axel:<br>
><br>
> Well, I didn't blame the PP, and I didn't mean to. My question is<br>
> quite simple. I was told that with a LDA PP, Ge has a vanishing or<br>
> negative band gap at Gamma point. But with this PP, it has a gap of<br>
> 0.50 eV (using experimental lattice) or 0.80 eV (after relaxation).<br>
> I'm not sure what I knew is correct, and that is the reason I wanted<br>
> another PP to verify.<br>
><br>
> Best,<br>
><br>
> Wei<br>
><br>
> On Thu, Oct 2, 2008 at 2:12 PM, Axel Kohlmeyer<br>
</div><div><div></div><div class="Wj3C7c">> <<a href="mailto:akohlmey@cmm.chem.upenn.edu">akohlmey@cmm.chem.upenn.edu</a> <mailto:<a href="mailto:akohlmey@cmm.chem.upenn.edu">akohlmey@cmm.chem.upenn.edu</a>>> wrote:<br>
><br>
> On Thu, 2 Oct 2008, willy kohn wrote:<br>
><br>
> WK> Hi, Axel:<br>
> WK><br>
> WK> Thanks a lot for your quick answer. I need to do some<br>
> calculations on some<br>
> WK> compound semiconductors of Ge. But the PP (Ge.pz-bhs.UPF)<br>
> provided in the<br>
> WK> PWSCF website yeided some results that I don't understand. So<br>
> I would like<br>
><br>
> perhaps it would be useful to explain in more detail what<br>
> is confusing you and what calculation you did with what input.<br>
> perhaps some people here can comment on it. it is always easy<br>
> to blame the pseudopotential (sometimes rightfully so), but<br>
> more often than not, the real cause is in not doing a calculation<br>
> correctly, or not using a pseudopotential correct.<br>
><br>
> WK> to use some other PP's to check if I did the calculation<br>
> correctly. Any<br>
> WK> suggestions?<br>
><br>
> i have a set of Ge pseudopotentials generated from parameters<br>
> for a norm-conserving troullier-martins potential that is in<br>
> the extended CPMD psp library. they have seen only very minimal<br>
> transferability testing (using an atomic code in bessel basis),<br>
> but so far seem to be ok, except for the OLYP one which has a<br>
> ghost in the s-channel.<br>
><br>
> i can send them to you in a private mail, if you are interested.<br>
> no guarantees etc...<br>
><br>
> cheers,<br>
> axel.<br>
><br>
> WK><br>
> WK> Best,<br>
> WK><br>
> WK> Wei<br>
> WK><br>
> WK> On Thu, Oct 2, 2008 at 11:54 AM, Axel Kohlmeyer<br>
</div></div>> <<a href="mailto:akohlmey@cmm.chem.upenn.edu">akohlmey@cmm.chem.upenn.edu</a> <mailto:<a href="mailto:akohlmey@cmm.chem.upenn.edu">akohlmey@cmm.chem.upenn.edu</a>><br>
<div><div></div><div class="Wj3C7c">> WK> > wrote:<br>
> WK><br>
> WK> > On Thu, 2 Oct 2008, willy kohn wrote:<br>
> WK> ><br>
> WK> > WK> Dear PWSCF users:<br>
> WK> > WK><br>
> WK> > WK> I have a quick question about using<br>
> WK> > WK> Hartwigsen-Goedeker-Hutter<<br>
> WK> ><br>
> <a href="http://cvs.berlios.de/cgi-bin/viewcvs.cgi/cp2k/potentials/Goedecker/abinit/pade" target="_blank">http://cvs.berlios.de/cgi-bin/viewcvs.cgi/cp2k/potentials/Goedecker/abinit/pade</a><br>
> WK> > >pseudopotential<br>
> WK> > WK> with PWSCF. Is there any converter to transfer the HGH pp<br>
> WK> > WK> format to UPF used in PWSCF?<br>
> WK> ><br>
> WK> > none that i am aware of.<br>
> WK> ><br>
> WK> > the GTH pseudopotentials are analytical in real and reciprocal<br>
> WK> > space and to incorporate them properly, one would have to do a<br>
> WK> > lot of programming. in the CPMD code (from <a href="http://www.cpmd.org" target="_blank">http://www.cpmd.org</a>)<br>
> WK> > they are treated as a special case, similar to ultra-soft psps.<br>
> WK> ><br>
> WK> > is there any particularly reason you'd need any of those?<br>
> WK> ><br>
> WK> > cheers,<br>
> WK> > axel.<br>
> WK> ><br>
> WK> ><br>
> WK> > WK><br>
> WK> > WK> Best,<br>
> WK> > WK><br>
> WK> > WK> Wei<br>
> WK> > WK><br>
> WK> > WK> Georgia Tech<br>
> WK> > WK><br>
> WK> ><br>
> WK> > --<br>
> WK> ><br>
> =======================================================================<br>
> WK> > Axel Kohlmeyer <a href="mailto:akohlmey@cmm.chem.upenn.edu">akohlmey@cmm.chem.upenn.edu</a><br>
</div></div>> <mailto:<a href="mailto:akohlmey@cmm.chem.upenn.edu">akohlmey@cmm.chem.upenn.edu</a>> <a href="http://www.cmm.upenn.edu" target="_blank">http://www.cmm.upenn.edu</a><br>
<div class="Ih2E3d">> WK> > Center for Molecular Modeling -- University of<br>
> Pennsylvania<br>
> WK> > Department of Chemistry, 231 S.34th Street, Philadelphia, PA<br>
> 19104-6323<br>
> WK> > tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel:<br>
> 1-215-898-5425<br>
> WK> ><br>
> =======================================================================<br>
> WK> > If you make something idiot-proof, the universe creates a<br>
> better idiot.<br>
> WK> ><br>
> WK><br>
><br>
> --<br>
> =======================================================================<br>
> Axel Kohlmeyer <a href="mailto:akohlmey@cmm.chem.upenn.edu">akohlmey@cmm.chem.upenn.edu</a><br>
</div>> <mailto:<a href="mailto:akohlmey@cmm.chem.upenn.edu">akohlmey@cmm.chem.upenn.edu</a>> <a href="http://www.cmm.upenn.edu" target="_blank">http://www.cmm.upenn.edu</a><br>
<div class="Ih2E3d">> Center for Molecular Modeling -- University of Pennsylvania<br>
> Department of Chemistry, 231 S.34th Street, Philadelphia, PA<br>
> 19104-6323<br>
> tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel: 1-215-898-5425<br>
> =======================================================================<br>
> If you make something idiot-proof, the universe creates a better<br>
> idiot.<br>
><br>
><br>
</div>> ------------------------------------------------------------------------<br>
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