LDA+U depend on the occupation of the different d orbitals. If you start with some particular, but arbitrary occupation (this isd what you might do, when starting from scratch and not from a converged GGA calculation), it may happen that you are trapped in a LOCAL minimum. (This could happen anyway, but is less likely when starting from GGA).
Am 19.11.2011 07:32, schrieb Yundi Quan: > Hi, > what is the purpose of first doing a LSDA calculation before turning on U? Is > it related to double counting? > > > _______________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien -- ----------------------------------------- Peter Blaha Inst. Materials Chemistry, TU Vienna Getreidemarkt 9, A-1060 Vienna, Austria Tel: +43-1-5880115671 Fax: +43-1-5880115698 email: pblaha at theochem.tuwien.ac.at -----------------------------------------