Electronic structure, thermomechanical and phonon properties of inverse perovskite oxide (Na₃OCl): An ab initio study

Abstract

Within first principles calculations, the electronic structure, thermodynamic, mechanical stability, magnetism, and phonon properties of the inverse perovskite (Na3OCl) have been summed up. The Birch-Murnaghan derived lattice constant and bond-lengths are identical, when compared to the experimental data. A direct energy gap of 2.18 eV observed from the band structure reveals the semiconducting nature of the present oxide. Also, the application of strain on electronic properties predicts the decrease in bandgap with respect to compressive strain and vice versa. The constituent nonmagnetic atoms in its crystal propose the total magnetic moment to be zero and the same is supported by susceptibility data. In addition to the negative Cauchy's pressure, the small bulk modulus compared to Young's modulus determined from elastic constants, possibly claims it as a brittle material. Also, the temperature dependent Gruneisen parameter (1.58) and Debye temperature (382.27 K) are determined to reveal the lattice thermal conductivity (κ = 6.48 W/mK) at room temperature.