First-principles calculations of optical and electronic properties of pure and Sm³⁺-doped TiO₂

First-principles calculations of the structural, electronic and optical properties of pure and Sm³⁺-doped anatase and rutile TiO₂ are reported. The list of the calculated properties is as follows: optimized crystal structures, band structures, partial and total densities of states (DOS), absorption spectra and dependence of the refractive index on the wavelength. Calculated results for the refractive indexes of pure compounds as a function of wavelength were fitted using the Sellmeyer equation with an infrared correction. Changes of physical properties of both compounds caused by Sm-doping are revealed and highlighted. Comparison of the calculated and experimental results is discussed.