Abstract:

The method of correlation functions for classical equilibrium many-particle systems, which accounts for a mean self-consistent field acting on each particle, has been formulated in the grand canonical ensemble representation. Inclusion of the self-consistent field effects into the formalism of correlation functions enables to describe systems in which the concentration of particles is not low. The account for the mean field is important for gases and liquids, where some notions used in the theory of rarefied gases lose their meaning, for example the mean free pass and pair collisions. The equation for the self-consistent field and the distribution function for arbitrary configuration energy is obtained from the requirement of minimum of the thermodynamic potential and it is shown that, if correctly formulated, the self-consistent field model leads to correct thermodynamic relations. The perturbation theory is constructed, based on the choice of the self-consistent field model as the main approximation. Thermodynamic functions, the heat capacities, the speed of sound and compressibility for a spatially homogeneous medium are calculated in the framework of the self-consistent field model for the pair interparticle interaction, as well as the main corrections to these quantities.

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