default values of LDAUU and LDAUJ in LDA+U method?

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gabral · #1 Post by **gabral** » Sat Dec 10, 2005 10:50 am

In LDA+U method, there are two paprameters: LDAUU and LDAUJ need to be specified. Are there default values for these two parameters in VASP? what's the rule to determine their values by hand?

Veronika · #2 Post by **Veronika** » Mon Dec 12, 2005 9:55 am

There are no default values, they depend on the system you want to investigate.
For further iformation on LDA+U read for example:
V. I. Anisimov, J. Zaanen and O. K. Andersen,
Phys. Rev. B 44, 943 (1991)
or the literature references that are given in the vasp-manual.
http://cms.mpi.univie.ac.at/vasp/vasp/node146.html

pankajnerikar · #3 Post by **pankajnerikar** » Wed Jul 19, 2006 5:20 pm

Hello,
I read the paper "V. I. Anisimov and O. Gunnarsson, Phys. Rev. B 43, 7570 (1991) "
calculation of + U in LDA+U is given (Equation 9). In this equation, there is a term called "spin-up eigen value". I wanted to know if this can be calculated from DFT calculations in VASP. If you look in Eq. 9 of the paper, Fo is calculated. For that i need this spin up eigen value and fermi energy. If I find this Fo, then according to Page 92 of VASP manual, I can find U and J. This is the only way I have come across to calculate these values. Please suggest.
Thanks
Pankaj