FREQUENCY-DEPENDENT AND WAVE-VECTOR-DEPENDENT SUSCEPTIBILITY OF WATER

The charge-susceptibility function of a flexible water model is invest igated using the theory of the dynamical dielectric function of intera ction-site model solvent developed by H. L. Friedman and his colaborat ors. The atom-atom pair correlation functions used as input in this ap proach were derived from results of molecular dynamic computer simulat ions. They were extended to larger separations by the use of integral equation theory techniques. It is pointed out that a more careful desc ription of long-ranged correlations can provide new information about the nature of the collective dynamics in water.