Condensed Matter Physics, 2012, vol. 15, No. 2, p. 23001:1-10
DOI:10.5488/CMP.15.23001           arXiv:1207.3249

Title: Ion clusters and ion-water potentials in MD-simulations
  Ph.A. Bopp (Universitéde Bordeaux, Department of Chemistry, 351 Cours de la Libération, Bât. A12, FR-33405 Talence cedex, France) ,
  K. Ibuki (Doshisha University, Department of Molecular Chemistry and Biochemistry, Kyotanabe, Kyoto 610-0321, Japan)

A well known, if little documented, problem in many molecular simulations of aqueous ionic solutions at finite concentrations is that unrealistic cation-cation associations are frequently found. One might suspect a defect in the ion-ion interaction potentials, about which not much is known. However, we show that this phenomenon can also be traced to the fact that, in the pair-potential approximation, the cation-water potentials are too deep compared with the other ones and we investigate this phenomenon in some detail. We then attempt to draw some general conclusions.

Key words: molecular dynamics simulations, aqueous ionic solutions, ion association
PACS: 02.70.-c, 02.70.Ns, 61.20.Ne, 61.20.Qg, 61.20.Gy, 61.20.Ja

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