Charge transfer and bonding in metallic oxides

We discuss the development of interaction potentials which explicitly allow for charge transfer in metallic oxides. The charge transfer is calculated self-consistently using a charge equilibration approach, which allows the amount of charge transferred to respond to the electrostatic environment. We model the metal-metal, metal-oxygen, and oxygen-oxygen interactions with Rydberg function pair potentials. By fitting the Rydberg potential parameters to the elastic and structural constants of the material, we arrive at an efficient model for the simulation of metallic oxides. We demonstrate the applicability of the model by describing some preliminary results on the rutile phase of titanium dioxide.