Proton momentum distribution of liquid water from room temperature toud the supercritical phase

摘要

Measurements of the proton momentum distribution n(p) in water fromud ambient conditions to above the supercritical point are compared withud theoretical calculations based on a recently developed polarizable waterud model. The n(p) along the H-bond direction is narrower in the denseud phases, and approaches that of the isolated molecule in the more diluteud phases. The theoretical model, which includes only electrostaticud interactions, is unable to explain the softening of the local potentialud experienced by the proton in the dense phases, but it accuratelyud predicts the n(p) for the dilute phases.