Structural, electronic, and optical characteristics of BaXCl3 (X = Li, Na) perovskites

The structural, electronic, and optical characteristics of the perovskites BaXCl3 (X = Li, Na) were thoroughly explored utilizing the full potential linear augmented plane wave approach within the density functional theory framework. When calculating structural properties, the exchange-correlation interactions were studied using the GGA-PBEsol functional, whereas when computing electronic and optical properties, they were analyzed using the TB-mBJ functional. The Equilibrium lattice parameters and bulk modulus were calculated by fitting total energy as a function of volume to the Birch-Murnaghan equation of state. Energy band dispersions estimated using the TB-mBJ method reveal that BaLiCl3 has an indirect R-Gamma-type bandgap of 5.57 eV, while BaNaCl3 exhibits a direct Gamma-Gamma-type bandgap of 5.59 eV. Densities of state diagrams were used to further understand the characteristics of the energy bands. The Frequency dependency of the dielectric function, absorption coefficient, refractive index, optical reflectivity, and energy loss function was investigated over the energy range of 0 to 30 eV. The computed optical spectra indicate that these perovskites have substantial promise for UV-related applications.