The concept of effective density and the closed integrofunctional equation for a radial function of a simple liquid

The thermodynamically consistent concept of effective density, similar to the idea of an acting field in statistical thermodynamics, is introduced. Assuming a linear functional relation between the effective and true densities (the packet approximation), a generating functional is constructed and from it, in the usual way, the closed integrofunctional equation for a radial function is obtained. Some properties of the obtained equation are investigated, including its relation to known integral equations, and a possible scheme for its solution, by the method of iteration, is presented. © 1976 Plenum Publishing Corporation.