Title: Potential of mean force between ions in infinitely diluted simple short-range models of aqueous electrolytes
Authors: L.Vlček (E. Hala Laboratory of Thermodynamics, ICPF, Acad. Sci., Rozvojova 135, 165 02 Prague 6 - Suchdol, Czech Republic) , I.Nezbeda (E. Hala Laboratory of Thermodynamics, ICPF, Acad. Sci., Rozvojova 135, 165 02 Prague 6 - Suchdol, Czech Republic; Physics Department, J. E. Purkyn\ve University, 400 96 Ústí n. Lab., Czech Republic)

As an attempt to assess the effect of the long-range electrostatic interactions in solutions of electrolytes, a simple short-range model (SSM) of electrolytes made up of primitive water and primitive ions (i.e., ions whose Coulombic interaction with water has been replaced by a triangular-well interaction) has been considered to compute the potential of mean force. The sizes of the primitive ions have been set so as to approximate realistic NaCl, LiI, and CsCl electrolytes. It is shown that despite the missing long-range Coulombic interaction the model captures the basic features of real electrolytes while the indirect, i.e. water mediated, potential of mean force in the SSM is in qualitative agreement with that of realistic models.

Key words: aqueous electrolytes, simple short-range model of electrolytes, primitive water, primitive ions, potential of mean force
PACS: 05.20.Jj