Large-scale quantum-chemical simulations of the diffusive hopping of empty cation and anion vacancies, as well as F+ and F centers, in crystals were performed. The atomic configurations for 224-site clusters and charge density distributions were analyzed for equilibrium and saddle-point configurations during defect hopping. It was found that the relevant activation energy for diffusion increased in the order: Va  F+  F-center.

A.I.Popov, E.A.Kotomin, M.M.Kuklja: Physica Status Solidi B, 1996, 195[1], 61-6