Calculations on Alkali and Halide Ion Hydration

Potential energy surfaces of ion‐water molecule interactions have been calculated using a classical model. The ions considered were the alkali and halide ions. The interaction energy was represented as a sum of electrostatic, polarization, dispersion, and repulsion energy terms. The calculation yielded the energy of the ``hydration'' reaction: ${\mathrm{H}}_2\mathrm{O}+\mathrm{ion}\to \mathrm{ion}({\mathrm{H}}_2\mathrm{O})$ as well as information on the configuration and the flexibility of the ion‐water bond. Possible consequences of this calculation for certain hydration properties (especially ``structure making'' and ``structure breaking'') are discussed.