The calculation of viral coefficients and thermodynamical functions of a system of neutral and charge particles with the pseudopotential of special form

Summary form only given. It is known that the divergence of virial and group expansion for thermodynamical values of dense gases in the low-temperature region is stipulated by the absolute values of the virial coefficients B/sub k/(T) (k=2,3,...) negative significance at T*=T//spl epsi/<1 (were /spl epsi/ is the energy of gas molecule dissociation). At the same time the second virial coefficient of the pair of interacting particles, which are able to form connected states (atom-atom, atom-ion, etc.) can be presented as a sum of both discrete and continuous spectrum: B/sub 2/=B/sub 2//sup d/+B/sub 2//sup c/. After the selection of the discrete part of the spectrum, responded to the connected states of the molecule (molecular ion), the region of classically accessible volume of phase space, corresponding to interaction in the continuous spectrum appreciably changes. In this work it is found that the temperature dependence of the second and the third virial coefficients for some pair additive spherically symmetrical interaction potentials of neutral and charged particles without and with accounting for the limiting classically accessible region of volume of phase space, brought about connected states formation in 2- and 3- particles complexes.