First-Principles Study of Electronic Structure and Optical Properties of Cubic Perovskite CsCaF₃

Electronic, structural and optical properties of the cubic perovskite CsCaF₃ are calculated by using the full potential linearized augmented plane wave (FP-LAPW) plus local orbitals method with generalized gradient approximation (GGA) in the framework of the density functional theory. The calculated lattice constant is in good agreement with the experimental result. The electronic band structure shows that the fundamental band gap is wide and indirect at (Γ–R) point. The contribution of the different bands is analyzed from the total and partial density of states curves. The charge density plots show strong ionic bonding in Cs-F, and ionic and weak covalent bonding between Ca and F. Calculations of the optical spectra, viz., the dielectric function, optical reflectivity, absorption coefficient, real part of optical conductivity, refractive index, extinction coefficient and electron energy loss, are performed for the energy range 0–30 eV.