Electronic structure and physical properties of NbSi2

We have investigated the optical properties of NbSi2 experimentally and theoretically. The reflectivity and ellipsometry measurements were performed on single crystals with two light polarizations. From these the optical conductivity and the complex dielectric function were obtained from 0 to about 6 eV. The measured optical functions were compared with those calculated using local density functional theory and the linear muffin-tin orbital method. The calculated electronic structure is analyzed using orbital projected densities of states (DOS) and the optical functions are interpreted in terms of interband transitions. We, furthermore, compare the calculated DOS with previously measured x-ray photoemission spectra and bremsstrahlung isochromat spectra. We calculated some soft x-ray emission spectra and compared them with experiments. We find generally excellent agreement between theory and all experiments.