First principles study of the electronic properties of MgO under pressure

Abstract

We have studied the electronic properties of MgO by first principles (CASTEP program). The calculated band gap of MgO shows MgO is an insulator. Pressure increases the band gap from 4.253 to 7.585 eV. The band above the Fermi level shifts to higher energy, while the band below the Fermi level shifts to lower energy. The shift comes from effect of pressure. The density of states (DOS) have been calculated and the relations between band and DOS have been discussed. The DOS also have shift and the shifts is according to the shifts in band. The electronic properties have also been calculated. We also find the pressure shifts the electronic properties to higher energy. The electronic shift come from the increased band gap. Our result provides a reference for future experiments.