The electronic and optical properties of the fluoroperovskite BaXF3 (X = Li, Na, K, and Rb) compounds

We present ab initio theoretical study of the structural, electronic and optical properties for fluoroperovskite BaXF3 (X = Li, Na, K, and Rb) compounds using full potential linearized augmented plane wave method as implemented in Wien2k code. We employed the generalized gradient approximation as exchange–correlation potential. Our calculations show that these compounds have direct energy band-gap (Γ–Γ). The dielectric function, refractive index, extinction coefficient, absorption coefficient, and reflectivity are calculated. All structures in the optical response are shifted toward lower energies as moved from Li to Rb. Our calculated optical properties show considerable anisotropy at low and high energies.