A full potential all-electron calculation on electronic structure of NiO

Abstract

We perform a first principle calculation on NiO system, a prototypical correlated electronic system due to partial filled 3d electronic shell, using various density functional theory (DFT) and hybrid functional methods inclusion of spin polarization (SP), on-site Coulomb repulsion U and spin–orbit coupling (SOC) effects. It is shown that localized spin density approximation (LSDA) plus U (LSDA + U) correctly reproduce experimental lattice parameter, while spin polarization generalized gradient approximation (SP + GGA + U) obviously overestimates lattice parameter. LSDA + U/SP + GGA + U band gaps and magnetic moments are in agreement with experimental data, and correctly predict NiO to be an insulator. NiO undergoes a Mott–Hubbard metal–insulator transition (MIT) by addition of Coulomb interaction U. Our LSDA + SOC calculation shows that SOC further splitting of Ni d eg and t2g orbitals into dz2, dxy, dx2y2 and dxz + dyz orbitals, and SP nearly cancels out SOC effect, giving rise to symmetry of density of states (DOS) for spin-up and spin-down states, hence appearance of zero net magnetic moment. For LSDA + U + SOC calculation, combination effect of SP, U and SOC results in non-occupying of spin-up conduction band and a negligible density of states for spin-down states.