Energy levels and deformation potentials for rocksalt MgO

We have studied the high-pressure behavior of the electronic properties of periclase (MgO) using ab initio total energy calculations within the full-potential linearized augmented plane wave method in the framework of the density functional theory. We predict that at zero pressure MgO in the rocksalt structure is a semiconductor with a direct band gap of 5.35 eV We show that the material remains a direct band gap semiconductor under pressures up to 100 GPa. We report the pressure coefficients and deformation potentials of the three transitions Γ–Γ, Γ–X and Γ–L for the material in question. We also find that the valence band width increases monotonically with increasing pressure suggesting that the rocksalt MgO becomes less ionic under pressure.