Energy levels and deformation potentials for rocksalt MgO
Résumé
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.