Computer simulation of Cl− hydration in anion–water clusters

Ion–water cluster free energy computer simulation using some of most popular ion–water and water–water pair interaction models

“…The result of computer simulation of Cl À -water clusters properties obtained with the help of polarizable Shevkunov's interaction model [31] has been chosen in this paper as of possible reference points to verify the efficiency of the potential functions under consideration. The Shevkunov's model [31] has been already calibrated against experimental data on free energy and entropy of formation of clusters from the vapour.…”

“…The result of computer simulation of Cl À -water clusters properties obtained with the help of polarizable Shevkunov's interaction model [31] has been chosen in this paper as of possible reference points to verify the efficiency of the potential functions under consideration. The Shevkunov's model [31] has been already calibrated against experimental data on free energy and entropy of formation of clusters from the vapour. In the Shevkunov's model the interaction between water molecules was described by five-centre ST2 potential [42] plus the interaction between dipole moments induced in molecules by ion field and the interaction of these induced dipoles with the ST2 permanent charge distribution.…”

“…The detailed description of this method can be found elsewhere [31,[36][37][38][39][40][41] and the main ideas are as follows. The Gibbs energy to bind one water molecule from vapour to an ion-water cluster in reaction (1) at temperature T and under pressure p 0 is given by…”

“…Bicanonical ensemble Monte Carlo (BC MC) method was developed for calculating the incremental binding or attachment absolute Gibbs energies for clusters [28][29][30][31]. This method allows one to perform the fitting procedure of the potential parameters values to the free energies measured for real molecular clusters.…”

“…This method allows one to perform the fitting procedure of the potential parameters values to the free energies measured for real molecular clusters. With the help of this method many-body potential function Cl À -water interactions [31] and rather sophisticated interaction model for OH À -water system [32][33][34] have been constructed by a fitting procedure. It was shown with the help of BC MC method in [35] that the liquid based Å qvist's Na + -water potential adequately describes the experimental data on attachment absolute Gibbs energy for corresponding clusters in gas-phase.…”