Ab initio calculation of the optical and photoelectron properties of RuO2.

The optical and photoemission properties of ${\mathrm{RuO}}_{2}$ in the rutile structure have been examined, using the ab initio self-consistent energy-band structure. The semirelativistic extended linear augmented-plane-wave method was employed. Our calculated spectra of the anisotropic complex dielectric function (DF) agree well with experiment. The origin of the anisotropy of the experimentally observed structure in the DF spectra at \ensuremath{\Elzxh}\ensuremath{\omega}=1 eV has been elucidated. Comparison of the calculated ultraviolet photoemission spectrum for \ensuremath{\Elzxh}\ensuremath{\omega}=21 eV with experiment suggests that indirect transitions play an important role in formation of the spectrum.