Three- and Four-Site Models for Heavy Water: SPC/E-HW, TIP3P-HW, and TIP4P/2005-HW

Heavy water or deuterium oxide, D₂O, is used as solvent in various biophysical and chemical experiments. To model such experiments with molecular dynamics simulations, effective pair potentials for heavy water are required that reproduce the well-known physicochemical differences relative to light water. We present three effective pair potentials for heavy water, denoted SPC/E-HW, TIP3P-HW, and TIP4P/2005-HW. The models were parametrized by modifying widely used three- and four-site models for light water, with aim of maintaining the specific characteristics of the light water models. At room temperature, the SPC/E-HW and TIP3P-HW capture the modulations relative to light water of the mass and electron densities, heat of vaporization, diffusion coefficient, and water structure. TIP4P/2005-HW captures in addition the density of heavy water over a wide temperature range.