A model for the fragile-to-strong transition in water

Abstract

A model based on the existence of two different competing local structures in water is described. It is shown that it can explain the transition between fragile and strong behaviour that supercooled water undergoes at around 220 K. The high-temperature behaviour is similar to that observed in standard fragile glass formers. The strong behaviour at low temperatures is associated with the existence of a remanent configurational entropy arising from the possibility of locally choosing between the two possible environments.