Ab initio simulation of the electron structure and optical spectroscopy of ErRhGe compound

The results of investigation of the electronic structure and optical properties of ErRhGe are presented. The band spectrum of this compound is calculated in the local electron spin density approximation with correction for strong electron interactions in the 4$f$ shell of the rare-earth metal (LSDA + U method) with allowance for the spin polarization. The optical constants of the compound are measured, and a number of spectral and electronic characteristics are determined by the ellipsometric method in a wide range of wave-lengths. Structural features of the optical conductivity spectrum in the interband absorption region are interpreted on the basis of the calculated electron state density.