Neutron diffraction studies of H2O/D2O at supercritical temperatures. A direct determination of gHH(r), gOH(r), and gOO(r)

Abstract

Neutron diffraction studies are reported on H₂O at temperatures of 300 and 400 °C. The method of isotopic substitution is applied to three mixtures of H₂O and D₂O, and the diffraction data are used to determine the three radial distribution functions g_HH(r), g_OH(r), and g_OO(r). These results can be used to discuss changes in nearest neighbor structure between water molecules, and to assess the degree of usefulness of representative (usually pairwise) model potentials.