Variable-lattice model of multi-component systems. 1. General consideration

The paper contains a development of the previously proposed generalized lattice model (GLM). In contrast to usual lattice models, the difference of the specific atomic volumes of the components is taken in account in GLM. In addition to GLM, the dependence of the specific atomic volumes on local atomic environments taken into account in new variable-lattice model (VLM). Thermodynamic functions of multi-component homogeneous phases in the VLM are obtained. Equations of equilibrium between gaseous and condensed phases are derived. PACS: 05.20.-y, 05.70.-a, 82.65.+r Key Words: Lattice models, Free energy, Phase equilibrium, Long-range and short-range inter-atomic potentials