Abstract
We have applied the polarizable electropole model of water and of water–ion interaction to molecular dynamics simulations of aqueous microclusters of alkali metal cations and halogen anions in the temperature range 150–400 K. This model effectively correlates observed enthalpies of formation; it is especially reliable for the larger alkali metal cations. Our simulations show unambiguous evidence of hydrogen atom inequivalency in the anion mono‐ and dihydrates over the temperature range studied. For the analogous cation hydrates, the structures are symmetric. We find two solvation shells in the larger microclusters; the largest ions have the fewest water molecules in their first solvation shells. The iodine and cesium inner solvation shells appear to contain only three and four water molecules, respectively. The structure of the anion hydrates strongly suggests that their stability arises in part from water–water binding.