[Pw_forum] second energy parameter setting in RRKJ USPP

[明文美]

Dear Prof. Stefano Baroni and Prof. Hande Toffoli:
 
 
 
  Thanks for all your helpful suggestion.I understand your useful comments.
 
 
Best regards.
 Wenmei> From: baroni at sissa.it> To: pw_forum at pwscf.org> Date: Mon, 11 Aug 2008 21:42:18 +0200> Subject: Re: [Pw_forum] second energy parameter setting in RRKJ USPP> > Dear Wenmei:> > besides the very sound suggestion by Hande, I would also recommend > that you take a glance at any (possibly, old) textbook in elementary > quantum mechanics. Why old? Because modern texts often given > elementary stuff for granted, which usually it is not.> > Coming to the specific issue that you raise. The number of nodes in > the solution of a 1D Schroedinger equation depends on the energy > parameter. The lower the energy, the fewer the nodes. Of course, for > an arbitrary energy parameter the resulting wavefunction is not > normalizable, that is why it has to be discarded, but for very > special, discrete, values, and energy is quantized. It is interesting > to understand "intuitively" how quantization of energy comes about. As > you rise the energy from any given value, the outer node moves out > furthhr and futher from the origin, but the number of nodes stays > constant if you do not change the energy too much. If the energy is > raised too much, a further node will appear. For some critical value > of the energy, the "extra" node will be at infinity: that's when an > energy eigenvalue is crossed.> > I do not expect that, if you have never heard about similar > arguments, you will understand mine, which have been stated rather > sloppily. Actually, if you decide to study this matter in a serious > book, your ability to understand my "sloppy arguments" will be a check > of your actual understanding of the serious arguments expounded in the > book.> > Hope this helps, a bit> Stefano> > On Aug 11, 2008, at 6:36 PM, Hande Ustunel wrote:> > > Dear Wenmei,> >> > I usually look at the output of the all-electron calculation and > > choose an> > energy close to the ae orbital energy. Once I manage to generate the> > pseudopotential I go as far away as possible from that reference > > without> > upsetting the code.> >> > Hope this helps...> > Hande> >> > On Tue, 12 Aug 2008, [gb2312] Ã÷ÎÄÃÀ wrote:> >> >>> >> Dear all:> >>> >> I want to generate my own RRKJ type ultrasoft pseudopotential > >> with atomic code in PWSCF,> >> I encountered a very confusing situation:> >>> >> when I chose -0.20Ry as the second energy used to pseudize the 5s > >> orbit, the ld1.x always complains :> >> =================================================> >> from gener_pseudo : error # 1 too many nodes> >> =================================================> >> however if I change the energy to be -0.50Ry, the corresponding > >> complain disappeared.> >>> >> How should I choose these energy parameters to generate a good > >> pseudopotential and how should I have a> >> correct understanding of these parameters?> >>> >> Thanks very much .> >>> >> Wenmei> >>> >> My &inputp file is also listed as :> >>> >> 64D 3 2 10 0.00 1.00 2.004D 3 2 0 -0.20 1.00 > >> 2.005S 1 0 2 0.00 2.00 2.505S 1 0 0 -0.50 2.00 > >> 2.505P 2 1 3 0.00 2.66 2.985P 2 1 0 -0.20 2.66 > >> 2.98> >>> >>> >>> >>> >>> >> _________________________________________________________________> >> ¿ìÀ´¿´¿´ÕâЩèßäÓжය£¬±¬Ð¦£¡> >> http://cnweb.search.live.com/video/results.aspx?q=%E5%8F%AF%E7%88%B1%E7%8C%AB%E5%92%AA&Form=MEVHAA> >> > -- > > Hande Toffoli> > Department of Physics> > Office 439> > Middle East Technical University> > Ankara 06531, Turkey> > Tel : +90 312 210 3264> > http://www.physics.metu.edu.tr/~hande> >> > _______________________________________________> > 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
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