Atomistic simulations of copper oxidation and Cu/Cu₂O interfaces using charge-optimized many-body potentials

Presented is a charge-optimized many-body potential (COMB) for metallic copper and copper oxide systems based on an extended Tersoff formalism coupled with variable charge electrostatics. To faithfully reproduce interactions between molecular oxygen and the metal surface, the potential includes atomic polarizabilities via both a point dipole model and dynamic partial charges, both of which are equilibrated through an extended Lagrangian scheme. The potential is fit to a training set composed of both experimental and ab initio computational data for cohesive energies, formation enthalpies, elastic properties, and surface energies of several metallic and oxide phases as well as bond dissociation energies for molecular oxygen and several of its anions. The potential is used in molecular dynamics simulations to model the Cu(111)Cu ₂O(100) interface and the oxidation of the Cu (100) surface.