First-principles studies of the structural, electronic, and optical properties of a novel thorium compound Rb2Th7Se15

•The first theoretical analysis of the Rb2Th7Se15 properties is reported.•Structural, electronic and optical properties of Rb2Th7Se15 were calculated.•An indirect character of Rb2Th7Se15 band gap was confirmed.•Dependence of the refractive index on the wavelength was calculated.

The structural, electronic, and optical properties of a recently synthesized thorium compound Rb2Th7Se15 have been calculated in the density functional theory framework for the first time. The calculated direct band gap was 1.471 eV (generalized gradient approximation) and 1.171 eV (local density approximation), with both results being close to the experimental result of 1.83 eV. High covalency/iconicity of the Th–Se/Rb–Se bonds was demonstrated by calculating effective Mulliken charges of all ions. The polarized calculations of the complex dielectric function are presented; dependence of the calculated index of refraction was fitted to the Sellmeyer equation in the wavelength range from 500 to 2500 nm.

Graphical abstractCalculated band structure of Rb2Th7Se15.Figure optionsDownload full-size imageDownload as PowerPoint slide