Empirical force fields are widely used in molecular simulation studies, mostly when chemical reactivity is not operative. Due to the availability of plentiful experimental and firstprinciples quantum mechanical data, water is a popular testing application for developing new force field models and new approaches to developing models. Among the most widely used physics-based water models today are the TIP3P and TIP4P models introduced in the 1980s, which employ well-established functional forms dating back to the 1930s 9 consisting of a rigid molecular geometry, fixed atomic partial charges, and Lennard-Jones interactions.