Band-structure picture for MnO reexplored: A model GW calculation.

Abstract

We calculate ab initio the quasiparticle energies of MnO with a self-energy model derived from the $\mathrm{GW}$ approximation. We obtain good values of the energy gap (4.2 eV), magnetic moment (4.5 ${\ensuremath{\mu}}_{B}$), and on-site interaction $U$ ( $\ensuremath{\sim}8\mathrm{eV}$) and reproduce both energy and intensity of all one-particle features of the photoemission spectra. The highest occupied states are O $2p$--Mn $3d({e}_{g})$ antibonding combinations. The lowest empty state is delocalized with strong ( $\ensuremath{\sim}30%$) Mn $4s$ character.