QUASI-PARTICLE PROPERTIES OF FE, CO, AND NI

For narrow electronic bands in metals, we seek improvement over the local-density approximation (LDA) by including the on-site Coulomb interaction between localized electrons. For the 3d ferromagnetic series of Fe, Co, and Ni, by treating fluctuations to second order in the on-site interaction around the LDA solution, in comparison with experiment a distinct improvement over the conventional LDA is obtained for a number of properties: effective masses, x-ray photoemission spectra, and results derived from angle-resolved photoemission spectra, such as exchange splittings and quasiparticle bands. In addition, the predicted quasiparticle broadenings and satellite features, which are not present in standard LDA calculations, are in reasonable agreement with observation.