Ionic association in electrolyte solutions: A Voronoi Polyhedra analysis

J.C. Gil Montoro and J.L.F. Abascal

ABSTRACT

Voronoi Polyhedra (VP) analysis of ionic solutions generated via Monte-Carlo simulations for a wide range of concentrations and ionic charges are reported. The properties investigated are the VP volumes, VP surface shared with unlike/like-ions and VP non-sphericity configurational mean values distributions. The study shows that high concentrations favor a molten salt-like structure while low concentrations tend to disrupt such ordering so small aggregates are more likely. The degree of separation between these forms is strongly determined by the charge of the ions. In the limit of low concentrations/high ionic charge, small clusters with some chain-like character are present which anticipates several features characteristic of the low density liquid-gas transition of the restricted primitive model.