Supercooled Water and the Kinetic Glass Transition II: Collective Dynamics

TL;DR

This study investigates the collective dynamics of deeply supercooled SPC/E water, providing evidence that mode coupling theory effectively describes its slow alpha-relaxation despite differences in cage formation mechanisms.

Contribution

It offers detailed analysis of Q-vector dependence in supercooled water and supports applying mode coupling theory to systems with hydrogen-bond network formation.

Findings

Identification of a two-step relaxation process in supercooled water

Mode coupling theory describes alpha-relaxation in water despite network formation

Deep supercooling dynamics captured over 250 ns simulations

Abstract

In this article we study in detail the Q-vector dependence of the collective dynamics in simulated deeply supercooled SPC/E water. The evolution of the system has been followed for 250 ns at low T, allowing a clear identification of a two step relaxation process. We present evidence in favor of the use of the mode coupling theory for supercooled liquid as framework for the description of the slow alpha-relaxation dynamics in SPC/E water, notwithstanding the fact that the cage formation in this system is controlled by the formation of an open network of hydrogen bonds as opposed to packing constraints, as in the case of simple liquids.