About the first solvation shell of protonated hydrates: H3O+(H2O)6

摘要

AbinitioSCF and semiempirical calculations have been performed on some geometrical configurations of the system H3O+(H2O)6, with either three or four water molecules in the first solvation shell. The dispersion energy has been evaluated from perturbation theory. It is shown that the pair approximation overestimates the stability of the second category of structures. However, the present work confirms that geometries with either three or four water molecules in the first solvation shell are close in energy. Comparison is done with results obtained from several semiempirical expressions and parameters available in the literature.