Title: ANALYTIC SOLUTION OF THE WERTHEIM'S PY APPROXIMATION FOR THE SHIELDED STICKY-POINT MODEL OF ASSOCIATING LIQUID
Author(s): Yu.V.Kalyuzhnyi, Yu.Ju.Duda

The analytical solution of the Wertheim's Ornstein — Zernike equation closed by the Percus — Yevick (PY)-like approximation for the shielded sticky-point model of associating liquid is presented. This model generalizes the one-site dimerizing Wertheim model for the case of associating liquids in which the bonding radius may be less than the core radius. Our numerical analysis leads to the conclusion that the present PY-like approximation provides satisfactory description of the system if the formation of associates does not change substantially an excluded volume of the system. In addition a simple approximation which relates the fraction of monomers (undimerized particles) and the strength of associative interaction is proposed. The predictions of this scheme agree well with nearly exact results of Zhou and Stell for all values of bonding radius.