Diagrammatic approach to gas-liquid phase transition in statistical theory

Abstract

The lattice gas system is studied. In frameworks of statistical mechanics, it is proposed the analytic algorithm of approximations construction when pressure calculating. Algorithm is built on the basis of virial expansion using special small parameter ν. The parameter is introduced by the prescription of the corresponding ν-power weight to each Mayer diagram without contact vertexes. The obtained formulas describe the gas-liquid phase transition