Quantum and classical simulations of an excess proton in water

The dynamics of excess proton motion in bulk water is investigated through both quantum and classical molecular dynamics simulations. Results are given both for the dynamics of the excess proton itself, as well as for the solvent dynamics which influence it. The shuttling of the excess proton between two solvating water molecules has been modeled using the empirical valence bond EVB model of Lobaugh and Voth. A critical analysis of the methodology used to model the proton exchange barrier is also given.