DENSITY AND CHARGE CORRELATIONS IN WATER

The radial distribution functions for a central force model of water, derived fron a combination of computer simulation and integral equatio n techniques, are used to calculate the density-density and charge-cha rge structure factors. These quantities are compared with neutron scat tering measurements of light and heavy water. From the behaviour of th e density-density and charge-charge structure factors in the thermodyn amic limit of small wavenumbers, the extent of density and charge fluc tuations is estimated. In particular, the density fluctuations in wate r are found to extend to longer distances than charge fluctuates. The relations between the charge fluctuations and the behaviour of the sta tic dielectric function as well as some dynamical properties are discu ssed.