SUPERCOOLED WATER AND THE KINETIC GLASS-TRANSITION .2. COLLECTIVE DYNAMICS

In this article we study in detail the Q-vector dependence of the coll ective dynamics in simulated deeply supercooled extended simple-point- charge (SPC/E) water. The evolution of the system has been followed fo r 250 ns at low T, allowing a clear identification of a two-step relax ation process. We present evidence in favor of the use of the mode-cou pling theory for supercooled liquid as a framework for the description of the slow cr-relaxation dynamics in SPC/E water, notwithstanding th e fact that the cage formation in this system is controlled by the for mation of an open network of hydrogen bonds as opposed to packing cons traints, as in the case of simple liquids.