Taking account to short-range repulsive potential in describing charged-particle systems

It is shown that the term independent of the ionic charge present in the expressions for the pressure and free energy corresponding to the approximation of the second virial coefficient for the model of solid charged spheres of the same diameter r0, like the other terms of these expressions, is a function of the plasma parameter. Conditions are found such that the expressions for the thermodynamic functions of a completely ionized system described by the model of solid uncharged spheres corresponding to the approximation of the second virial coefficient transform to the equivalent expression of the second approximation of Debye-Hueckel theory, except for terms equivalent to the product of the plasma parameter and the ratio of r0 to the Debye radius