Short-range interionic potentials for the substitutional ${\mathrm{Cu}}^{+}$ ion in alkali fluorides and chlorides are derived using a methodology that provides self-consistent electronic-structure treatment of a molecular cluster of ions that includes the impurity, embedded in a shell model lattice. The derived potentials are used to calculate the activation energy for ${\mathrm{Cu}}^{+}$ diffusion by the cation vacancy mechanism in these materials. For the only case where an experimental value is available, namely, KCl:${\mathrm{Cu}}^{+}$, satisfactory agreement is found.

• Received 21 April 1988

DOI:https://doi.org/10.1103/PhysRevB.38.10083