Effect of Coulomb interaction on the band gap of NiO

Abstract

The band theory and local density approximation LDA predict NiO to be a metal but experimentally this material is known to be an insulator. To overcome this problem, we employ the LDA+U (where U is the on-site Coulomb interaction) technique in order to get the true nature of the material. We observed an increase in the band gap of the material as we gradually increase the value of U. Our result was compared with other works and that of experimental result.

Keywords: LDA+U; Electronic band gap; on-site Coulomb interaction