Localization in the self-interaction corrected density functional formalism

It is shown that the self-interaction corrected (SIC) local spin density (LSD) approximation accurately describes localized electron states in systems where the Coulomb interaction is large compared with the band width. The SIC method is applied to the Hubbard model in 1, 2 and 3 dimensions as well as to a model of (undoped) La2 CuO4. Considerable improvement over the standard LSD approach is found for such quantities as the total energy, the local spin moment and the energy gap. In particular, for La2 CuO4, SIC gives a somewhat too large antiferromagnetic moment, while LsD greatly underestimates the tendency to antiferromagnetism