THE SYMMETRY OF INTERATOMIC LATTICE POTENTIALS IN GENERAL CRYSTAL-STRUCTURES .1. BASIC THEORY

Within the framework of a generalized model of a multicomponent lattice gas, the symmetry properties of many-particle interatomic potentials are investigated. The relations of the invariance (with respect to the symmetry transformations) for the potentials and the relationships between their Fourier components are represented in a form convenient to check the symmetry adequacy of microscopic model potentials in real as well as in reciprocal space. The method of statistical-thermodynamic description of multicomponent solid solutions is suggested, taking into consideration the symmetry changes of interatomic potentials due to the structural phase transformations.