<div dir="ltr">Hi, Axel:<br><br>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.<br>
<br>Best,<br><br>Wei<br><br> <br><br><div class="gmail_quote">On Thu, Oct 2, 2008 at 2:12 PM, Axel Kohlmeyer <span dir="ltr"><<a href="mailto:akohlmey@cmm.chem.upenn.edu">akohlmey@cmm.chem.upenn.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="Ih2E3d">On Thu, 2 Oct 2008, willy kohn wrote:<br>
<br>
</div>WK> Hi, Axel:<br>
WK><br>
WK> Thanks a lot for your quick answer. I need to do some calculations on some<br>
WK> compound semiconductors of Ge. But the PP (Ge.pz-bhs.UPF) provided in the<br>
WK> PWSCF website yeided some results that I don't understand. So 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 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>
<div class="Ih2E3d"><br>
cheers,<br>
axel.<br>
<br>
WK><br>
WK> Best,<br>
WK><br>
WK> Wei<br>
WK><br>
</div>WK> On Thu, Oct 2, 2008 at 11:54 AM, Axel Kohlmeyer <<a href="mailto:akohlmey@cmm.chem.upenn.edu">akohlmey@cmm.chem.upenn.edu</a><br>
WK> > wrote:<br>
WK><br>
<div class="Ih2E3d">WK> > On Thu, 2 Oct 2008, willy kohn wrote:<br>
WK> ><br>
</div>WK> > WK> Dear PWSCF users:<br>
<div class="Ih2E3d">WK> > WK><br>
WK> > WK> I have a quick question about using<br>
</div>WK> > WK> Hartwigsen-Goedeker-Hutter<<br>
WK> > <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>
<div class="Ih2E3d">WK> > WK> Best,<br>
WK> > WK><br>
WK> > WK> Wei<br>
WK> > WK><br>
WK> > WK> Georgia Tech<br>
</div>WK> > WK><br>
WK> ><br>
WK> > --<br>
WK> > =======================================================================<br>
<div class="Ih2E3d">WK> > Axel Kohlmeyer <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>WK> > Center for Molecular Modeling -- University of Pennsylvania<br>
WK> > Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323<br>
WK> > tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel: 1-215-898-5425<br>
WK> > =======================================================================<br>
WK> > If you make something idiot-proof, the universe creates a better idiot.<br>
WK> ><br>
<div><div></div><div class="Wj3C7c">WK><br>
<br>
--<br>
=======================================================================<br>
Axel Kohlmeyer <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>
Center for Molecular Modeling -- University of Pennsylvania<br>
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 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 idiot.<br>
</div></div></blockquote></div><br></div>