1 Department of Chemistry and Biochemistry and Centre for Research in Molecular Modeling (CERMM) and ‡Department of Physics, Concordia University , Montréal, Canada.

This letter presents a method for the parametrization of semiempirical models for proton transfer reactions in water clusters. Two new models are developed: AM1-W, which is a reparameterization of the classic AM1 model, and AM1PG-W, which is a modified AM1-like model including a pairwise correction to the core repulsion function. Both models show good performance on hydrogen-bonding energies and on proton transfer energy profiles, which are of great importance for proton transfer reactions in...