AB-INITIO CALCULATION OF THE OPTICAL AND PHOTOELECTRON PROPERTIES OF RUO2

The optical and photoemission properties of RuO2 in the rutile structu re have been examined using the ab initio self-consistent energy-band structure. The semirelativistic extended linear augmented-plane-wave m ethod 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 ($) over bar h omega = 1 eV has been elucidated. Comparison of the calculated ultraviolet photoemission spectrum for ($) over bar h omeg a = 21 eV with experiment suggests that indirect transitions play an i mportant role in formation of the spectrum.