Self-consistent tight-binding atomic-relaxation model of titanium dioxide

We report a self-consistent tight-binding atomic-relaxation model for titanium dioxide. We fit the parameters of the model to first-principles electronic structure calculations of the band structure and energy as a function of lattice parameters in bulk rutile. We report the method and results for the surface structures and energies of relaxed (110), (100), and (001) surfaces of rutile TiO₂ as well as work functions for these surfaces. Good agreement with first-principles calculations and experiments, where available, is found for these surfaces. We find significant charge transfer (increased covalency) at the surfaces.