Theoretical and experimental studies of the system Ca+(H2O)n for n=1 to 10

Abstract
Monte Carlo calculations and gas phase mass spectrometry studies have been carried out on the system Ca+(H2O)n. The parameters used in the calculations to describe the interaction energy between Ca+ and a water molecule are deduced from quantum mechanical ab initio determinations. The clusters formation energies through the reaction Ca+(H2O)n−1+H2O ⇄ Ca+(H2O)n have been calculated for n=1 to 10 and determined from gas phase mass spectrometry for n=1 to 5. For n=6 to 10, theoretical work shows that, though the most stable structures have six water molecules in a first shell surrounding Ca+, the statistical distribution increases from 5.28 to 5.63, due to the presence of many stable configurations with five water molecules in the first shell. A comparison is done with the system H3O+(H2O)n.