PROBLEM OF CONDENSATION IN STATISTICAL PHYSICS

The author considers an accurate expression for the cluster expansion of the configuration integral of the system of interacting particles. Investigations of this expression indicate the beginning of the gas-liquid transition at the singularity points of isothermal compressibility. It has also been shown that the adequacy boundary of the virial equation of state corresponds to these points - not the virial range singularities. At the high density region the inappropriate behavior of the cluster expansion has been discovered that may be related to the infinite limits of the cluster integrals, i.e. their independency on density.