Hi Deyu, I have recently implemented a capability in the code that allows for using Hubbard U on two orbital manifolds per atom (e.g. d and s states of transition metals). If you are interested I can send you the code.
Regards Burak Himmetoglu Post-doctoral associate Department of Chemical Engineering and Materials Sciecne University of Minnesota, 421 Washington Av. SE Minneapolis, MN 55455 On Mon, Jan 30, 2012 at 10:25 AM, Deyu Lu <deyulu at yahoo.com> wrote: > Dear all: > I'm interested in doing DFT+U calculation on a single atom with > multiple > manifolds, and I'm wondering whether the code is available in some > developmental stage. > To be more specific, I'm looking at small Ce clusters and want to > understand how linear > response U of Ce changes according to the local chemical environment, > e.g., valence state > and spin state, etc. If I use only Ce 4f, I found chi0 and chi matrices > don't obey sum rule, > and in some cases, an eigenmode of chi0 and chi can be clearly identified > corresponding to > a uniform potential perturbation with a small negative eigenvalue. This > means there is an exchange > of the induced charge density between the 4f manifold and the background. > By looking at PDOS, a non-negligible 4f-5d and 4f-6s hybridization are > found right at LUMO, > however, the hybridization with nearby O 2p seems to be weaker. In order > to eliminate this error > during the chi0 and chi inversion and > obtain more accurate estimate on U, it makes sense to me to add Ce 5d and > 6s. This modification > is not quite obvious in set_hubbard_l.f90 and tabd.f90, since these > subroutines assume one channel > per atom type. > > Best regards, > Deyu Lu > > ************************************************ > Deyu Lu > Assistant Physicist, Theory & Computation Group > the Center for Functional Nanomaterials > Rm 1002, Building 735, Brookhaven National Lab > Upton, NY, 11973 > webpage: http://www.bnl.gov/cfn/people/Deyu_Lu.asp > ************************************************ > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120130/fe01925b/attachment.htm
