Hydrogen-bonding in light and heavy water under normal and extreme conditions

Our purpose is to report results of molecular dynamics (MD) simulation on light and heavy water modelled by a central force potential related to those proposed in the 1970s by Lemberg, Rahman and Stillinger. Quantum effects are taken into account by implementing in the MD code the Feynman–Hibbs quantum approximation. The evolution of the energetics, the structure and the diffusivity of the two isotopic species is investigated between ambient and supercritical conditions and compared with experimental data and with classical simulations as well. The accuracy of the results and the very low cost in computer time make the Feynman–Hibbs approach a possible alternative to the path integral simulation methods used in the literature.