Screened-exchange functional for the uniform-density electron gas

We examine the Wannier-function formulation of the self-interaction correction to the local-spin-density approximation (LSDA) for a uniform-density electron gas. We find that the formulation yields results with the following interesting features: (1) an eigenvalue spectrum, (k), closer to that of the Hartree-Fock approximation than that of the LSDA except near the Fermi level, (2) a k-dependent exchange contribution to (k) similar to the Hartree-Fock exchange, and (3) a density-of-states (DOS) which resembles that of the LSDA for energies near k=0 but which takes on the shape of the Hartree-Fock DOS near the Fermi level. We relate these features to a reduction of the effective screening of the long-range Coulomb interaction which occurs in the LSDA.