Crystal Structures of Zirconia from First Principles and Self-Consistent Tight Binding

The origin of the relative stability of the cubic, tetragonal, and monoclinic phases of zirconia $(\mathrm{ZrO}{}_{2})$ is investigated. To obtain accurate energies we adopt a new all-electron bandstructure approach within the local density approximation, based on muffin tin orbitals. We also develop a self-consistent tight-binding model with which to study the energies for different structures. The tight-binding model enables us to analyze ab initio and experimental phase stabilities in terms of ionic versus covalent effects, including polarization of the anions, and promises to be useful for rapid simulation of more complex systems.