Study of the hydroxyl ion in water. A combined quantum chemical and statistical mechanical treatment.

A combined quantum mechanical-statistical mechanical method has been used to study the behavior of the hydroxyl ion in water. The system is divided into three parts, a quantum core (the ion), 89 classical water molecules, and a dielectric continuum. The water molecules are represented using a polarizable potential. The first solvation shell consists of four water molecules, two linked by hydrogen bonds to the oxygen of the ion and the other two linked to the hydrogen of the ion. The intermolecular distances obtained are in the same range as those in previous calculations. The intramolecular bond length in the ion decreases by 0.09 au upon solvation relative to the gas-phase value