thank you - we really appreciate SB On Apr 2, 2010, at 10:44 PM, jia chen wrote:
> Dear Prof Stefano de Gironcoli, > > Thank you for your explanation. It is really helpful. > I have been using Quantum Espresso for a while. I like this project > very much and I hope I can do a little contribution to this community. > Since QE4.0, empty states feature in CP code didn't work anymore. I > added about ten lines to emptystartes.f90 module and it works in 4.1.1 > and 4.1.2. I know people have other methods to do it, but this feather > may be handy, so I attached the code which may be useful, just in > case, for someone. I am not a good programmer, I can do nothing more > than making it work... > > Best Regards > jia > On Fri, Apr 2, 2010 at 3:17 AM, <pw_forum-request at pwscf.org> wrote: >> Send Pw_forum mailing list submissions to >> pw_forum at pwscf.org >> >> To subscribe or unsubscribe via the World Wide Web, visit >> http://www.democritos.it/mailman/listinfo/pw_forum >> or, via email, send a message with subject or body 'help' to >> pw_forum-request at pwscf.org >> >> You can reach the person managing the list at >> pw_forum-owner at pwscf.org >> >> When replying, please edit your Subject line so it is more specific >> than "Re: Contents of Pw_forum digest..." >> >> >> Today's Topics: >> >> 1. starting_magnetization and magnetization optimization in >> pwscf (jia chen) >> 2. Re: starting_magnetization and magnetization optimization in >> pwscf (Stefano de Gironcoli) >> >> >> ---------------------------------------------------------------------- >> >> Message: 1 >> Date: Thu, 1 Apr 2010 16:26:31 -0400 >> From: jia chen <jiachen at princeton.edu> >> Subject: [Pw_forum] starting_magnetization and magnetization >> optimization in pwscf >> To: pw_forum at pwscf.org >> Message-ID: >> <y2sf033174e1004011326m6b76da56r56a8fe080e44ab2d at mail.gmail.com> >> Content-Type: text/plain; charset=ISO-8859-1 >> >> Dear All, >> >> Pwscf has a very nice feature that can set initial magnetism of a >> certain kind of atom by starting_magnetization. It is working very >> well for me. But I would like to know more about how this is really >> working in cp code, during magnetization optimization calculations. It >> is too much for me to read the code to get the answer. So I would like >> to give a guess of basic idea of this process. >> >> When we start a calculation with initial atomic wave functions. Pwscf >> code can give atomic occupations of spin up and down whose ratio >> satisfy the value of starting_magnetization. During the calculation, >> pwscf can adjust the occupation number after each diagonal step >> according to orbitals energies because pwscf goes with a bunch of >> empty states. Then there can be "electron flow" between spin up and >> down. Basically, that's I guess how pwscf does magnetization >> optimization. >> >> Can you tell me what is the actual process pwscf goes though in this >> kind of magnetization optimizations? Any comments are very welcome. >> Thank you in advance. >> >> Best Wishes >> -- >> Jia Chen >> >> Dept of Chemistry >> Princeton University >> Princeton, NJ 08544 >> >> >> ------------------------------ >> >> Message: 2 >> Date: Thu, 01 Apr 2010 23:17:50 +0200 >> From: Stefano de Gironcoli <degironc at sissa.it> >> Subject: Re: [Pw_forum] starting_magnetization and magnetization >> optimization in pwscf >> To: PWSCF Forum <pw_forum at pwscf.org> >> Message-ID: <4BB50D7E.6000905 at sissa.it> >> Content-Type: text/plain; charset=ISO-8859-1; format=flowed >> >> Dear Jia Chen, >> the starting magnetization variable is used to define the initial >> charge density in a scf run in pwscf. >> This density is used to build the first KS potential which thus >> results to have a magnetically broken symmetry. >> The resulting spin-up and spin-down hamiltonians are diagonalized and >> the Fermi energy located from the constraint on the total number of >> electrons (the system must be treated as a metal and a number of empty >> states are present). >> This determines the output density and since the potential is >> "magnetically ordered" the density also is if the system likes so. >> Then the code mixes in and out densities and builds a new guess for >> the input density and hence the new KS potential and so on... >> So starting magnetization really enters only in PW/atomic_rho.f90 >> which is used to build the starting guess for the input charge density as >> >> rho_up = sum_s (1.0+starting_magnetization_atom_s)/2 * >> unpolarized_rho_atom_s >> rho_dw = sum_s (1.0-starting_magnetization_atom_s)/2 * >> unpolarized_rho_atom_s >> >> Hope this helps, >> >> stefano >> >> >> jia chen wrote: >>> Dear All, >>> >>> Pwscf has a very nice feature that can set initial magnetism of a >>> certain kind of atom by starting_magnetization. It is working very >>> well for me. But I would like to know more about how this is really >>> working in cp code, during magnetization optimization calculations. It >>> is too much for me to read the code to get the answer. So I would like >>> to give a guess of basic idea of this process. >>> >>> When we start a calculation with initial atomic wave functions. Pwscf >>> code can give atomic occupations of spin up and down whose ratio >>> satisfy the value of starting_magnetization. During the calculation, >>> pwscf can adjust the occupation number after each diagonal step >>> according to orbitals energies because pwscf goes with a bunch of >>> empty states. Then there can be "electron flow" between spin up and >>> down. Basically, that's I guess how pwscf does magnetization >>> optimization. >>> >>> Can you tell me what is the actual process pwscf goes though in this >>> kind of magnetization optimizations? Any comments are very welcome. >>> Thank you in advance. >>> >>> Best Wishes >>> >> >> >> >> ------------------------------ >> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> >> End of Pw_forum Digest, Vol 34, Issue 5 >> *************************************** >> > > > > -- > Jia Chen > > Dept of Chemistry > Princeton University > Princeton, NJ 08544 > <emptystates.f90>_______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum --- Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste http://stefano.baroni.me [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) La morale est une logique de l'action comme la logique est une morale de la pens?e - Jean Piaget Please, if possible, don't send me MS Word or PowerPoint attachments Why? 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