Pair distribution functions of a binary Yukawa mixture and their asymptotic behavior

Based on an analytic solution of the mean spherical model for a binary hard sphere Yukawa mixture, we have examined the pair distribution functions g(ij)(r), focusing, in particular, on two aspects: (i) We present two complementary methods to compute the g(ij)(r) accurately and efficiently over the entire r range. (ii) The poles of the Laplace transforms of the pair distribution functions in the left half of the complex plane close to the origin determine the universal asymptotic behavior of the g(ij)(r). Although the meaning of the role of the subsequent poles-which typically are arranged in two branches-is not yet completely clear, there are strong indications that the distribution pattern of the poles is related to the thermodynamic state of the system.