Energy Band Structure and Optical Properties of LiNaSO4 Crystals

Abstract

The energy band structure of a LiNaSO₄ has been calculated within the framework of density functional theory for space group P31c. It has been established that bandgap width E_g in the GGA approximation is 5.49 eV. The valence band top is generally formed of oxygen p-electrons, while the conduction band bottom is composed of lithium and sodium s-states. The effect of the cationic substitution Na → K → Rb → NH₄ on the electron structure of LiBSO₄ group crystals is considered. Based on the calculated dielectric functions, the spectral dependences of the refractive indices and extinction coefficient of a crystal were calculated and compared with experimental data.