Multipole Theory of the Polarization of Solids by Point Defects. II. The Point Charge Approximation

The method for calculating the polarization energy of crystals by point defects presented and developed in the first part of the paper is applied to concrete single defects (vacancies, V k centres) in alkali halides. (The point‐charge approximation is used.) The continuous approximation involved is examined in detail for a vacancy as an example, the results obtained are compared with the exact calculations of polarization energy and dipole moments. The formation energies of vacancies in six alkali halides are estimated. The semiempirical INDO cluster calculation of the V k centre being accompanied with an additional polarization calculation is used to obtain the equilibrium distance within the Cl quasimolecule in KCl.