ELECTRONIC GROUND-STATE OF MNO, FEO, COO AND NIO WITHIN THE LSDA+U APPROXIMATION

The LCAO formalism based on the local spin density approximation (LSDA +U) has been used to perform self-consistent spin-polarized electronic density calculations on MnO, FeO, CoO and NiO. The intrasite electros tatic Coulomb interaction U drives a systematic gap opening within the partially occupied t(2g down arrow) band for FeO and CoO and enlarges the forbidden band for MnO and NiO. The theoretical band gap is match ed with the experimental one by adjusting U considered as a parameter. The four oxides are termed as Mott-Hubbard insulators owing to the pr evalence of the d functions in the upper valence band. Copyright (C) 1 996 Elsevier Science Ltd