Abstract
Am interionic potential model has been proposed for the study of some crystal properties of mixed diatomic solids. This potential consists of the long-range Coulomb and three-body interactions and the short-range van der Waals attraction and overlap repulsion of Hafemeister and Zarht type (1967). The hardness parameter rho is obtained from overlap integrals. The authors have used this potential to calculate cohesive energy, third-order elastic constants and pressure derivatives of second-order elastic constants and some other thermophysical properties of AgCl-AgBr mixed crystals. The results agree fairly well with the available experimental data.