Predictions of Electronic, Transport, and Structural Properties of Magnesium Sulfide (MgS) in the Rocksalt Structure

Abstract

We report results from ab-initio , self-consistent density functional theory (DFT) calculations of electronic, transport and bulk properties of rock salt magnesium sulfide (MgS). In the absence of experimental data on these properties, except for the bulk modulus, these results are predictions. Our calculations utilized the Ceperley and Alder local density approximation (LDA) potential and the linear combination of Gaussian orbitals (LCGO). The key difference between our computations and other previous ab-initio DFT ones stems from our use of successively larger basis sets, in consecutive, self-consistent calculations, to attain the ground state of the material. We predicted an indirect ( Γ -X) band gap of 3.278 eV for a room temperature lattice constant of 5.200 Å . We obtained a predicted low temperature indirect ( Γ -X) band gap of 3.512 eV, using the equilibrium lattice constant of 5.183 Å . We found a theoretical value of 79.76 GPa for the bulk modulus; it agrees very well with the experimental finding of 78 ± 3.7 GPa.