STRUCTURAL AND ELECTRONIC-PROPERTIES OF TITANIUM-DIOXIDE

Calculations have been performed using "soft-core" ab initio pseudopotentials constructed within the local-density approximation, and a plane-wave basis for the structural and electronic properties of titanium dioxide in the rutile structure. The ground-state structural and cohesive properties were obtained by self-consistently minimizing the total energy with respect to the structural parameters a, c, and u. Our calculated cohesive and structural properties at ambient pressure agree to within 5% and 1% of experimental values, respectively. The structural and elastic properties under pressure are also in good agreement with experiment. The interplay between ionic and covalent bonding between Ti and 0 is investigated through the valence-charge density and compared to experimental charge-deformation maps. The electronic band structure is found to be in good agreement with experimental results. We analyze the optical spectrum of rutile and obtain agreement with experiment away from the fundamental absorption edge. Our study suggests material properties for early-transition-metal oxides are well reproduced within the local-density approximation.