On the critical behavior of the Percus-Yevick equation for nontruncated potentials

Abstract

We present a qualitative analysis on the influence of truncating a long‐ranged potential on the critical behavior of a fluid described by the Percus–Yevick equation. It is shown that a nonclassical equation of state for truncated potentials can be compatible with a classical one in the long‐range limit. Our main assumption is that the dominant part of the difference between both equations of state is a regular function driven by the asymptotic behavior of the direct correlation function. The results are applied to the case of a Lennard‐Jones potential. Comparison with available numerical results is quite satisfactory.