SELF-INTERACTION CORRECTION VIA THE MOMENTUM DISTRIBUTION

The self-interaction correction (SIC) to local-spin-density functional theory is important in antiferromagnetic insulators such as transition metal oxides. To understand better the role of SIC in such systems, Svane and Gunnarsson introduced a discrete local-density functional for the Hubbard model. It is shown that their results, and further results, are obtained rather simply by expressing the energy as a functional of the momentum distribution. New results are given for the energy of the two-dimensional Hubbard model. The method is extended to calculate the transverse wave-vector-dependent susceptibility in a simple case.