Thermodynamic perturbation theory for systems with short-range parts of the interparticle interaction potential

A relation is obtained between thermodynamic quantities of a system of particles interacting through pair potentials having the same long-range part and varying short-range parts. It is assumed that either the perturbation or the long-range part of the potential are large with respect to temperature. The result has the form of an expansion similar to a cluster. Types of linked diagrams are considered, which determine cluster integrals.