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.