DYNAMICS OF BONDED NETWORKS WITH 2 ENERGY SCALES

We model the dynamics of a molecular network with two distinct energy scales E1E2. A novel critical bond dynamics is shown to arise due to screening. We identify an order parameter and determine the related exponent at the critical temperature Tc. Above Tc, the dynamics is characterized by a power-law distribution of bond lifetimes with an exponential cutoff at a time that diverges at Tc. Our picture is applied ot liquid water. © 1990 The American Physical Society.