The coupling of long and short range correlations in ISM liquids

Abstract

A simple modification of the HNC-like closure within the extended RISM equation formalism is considered which assures that the asymptotic form of the site-site direct correlation functions is consistent with the dielectric constant. The short ranged structural results obtained with the modification are compared to those following from the original closure for three strongly polar diatomic models, with the result that only very small differences are found. These results demonstrate both that the short ranged results are only weakly coupled to the asymptotic amplitudes, and that the latter can potentially be corrected in a relatively straightforward manner.