OPTICAL-PROPERTIES OF TITANIUM-DIOXIDE IN THE RUTILE STRUCTURE

We present first-principles calculations for the optical properties of titanium dioxide in the rutile structure. The electronic band structure has been calculated self-consistently within the local-density approximation using ab initio pseudopotentials and a plane-wave basis. Optical properties are determined from the imaginary part of the dielectric function and compared to experiment. Although our local-density calculation underestimates the band gap, our results show that the optical properties for this early-transition-metal oxide are in surprisingly good agreement with experiment away from the fundamental absorption edge. We attribute this good agreement to the ability of the local-density approximation to yield accurate matrix elements between occupied and empty states.