Heat of formation of solid solution of alkali halides

Based on a semicontinuum model, the electrostatic, the polarisation, and the repulsive energy change of a lattice is calculated numerically, as a function of the relaxation of the nearest neighbouring ions of a substitutional impurity in an alkali halide crystal. It is found that for a particular displacement, the total energy change of the lattice is a minimum. Thus the heat of formation of a dilute solid solution is obtained. Here, we report calculations on the heat of formation of the following systems-Na⁺ in LiCl, Li⁺ in NaCl, K⁺ in NaCl, Na⁺ in KCl, Rb⁺ in NaCl, Na⁺ in RbCl, F^? in NaCl, Cl^? in NaF. Br^? in NaCl and Cl^? in NaBr.