The partial pair correlation functions of dense supercritical water

Neutron diffraction measurements of heavy water and of two isotopic H 2 O/D 2 O mixtures at supercritical state ( T = 380 °C and ρ D 2 O = 0.73 g/cm 3 ) are presented. In combining the set of neutron diffraction data with previous X-rays measurements of Yamanaka et al. ( J. Chem. Phys. , 101 (1994) 9830), it has been possible by using a Monte Carlo method to reach the partial pair correlation functions g OH ( r ), g HH ( r ) and g OO ( r ). The results are compared with molecular-dynamics simulations using the SPCE pair potential for water. These new results confirm that hydrogen bonding is still present in dense supercritical water.