Intra-atomic and interatomic Coulomb contributions to the total energy are added to the tight-binding theory of bonding in simple ionic solids. They are found to remove the principal discrepancies with experiment found earlier for the bulk modulus and Grüneisen constant for the alkali halides and alkaline-earth chalcogenides. The analysis is extended also to predict the full elastic tensor for these systems and the pressure dependence of that tensor, in good accord with experiment where it exists.

• Received 17 October 1988

DOI:https://doi.org/10.1103/PhysRevB.39.10325