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 -------------- next part -------------- A non-text attachment was scrubbed... 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