The dynamics of supercooled water can be predicted from room temperature simulations

Abstract

There is strong interest in understanding the behavior of water in its supercooled state. While many of the qualitative trends of water dynamical properties in the supercooled regime are well understood, the connections between the structure and dynamics of room temperature and supercooled water have not been fully elucidated. Here, we show that the reorientational time scales and diffusion coefficients of supercooled water can be predicted from simulations of room temperature liquid water. Specifically, the derivatives of these dynamical time scales with respect to inverse temperature are directly calculated using the fluctuation theory applied to dynamics. These derivatives are used to predict the time scales and activation energies in the supercooled regime based on the temperature dependence in one of two forms: That based on the stability limit conjecture or assuming an equilibrium associated with a liquid-liquid phase transition. The results indicate that the retarded dynamics of supercooled water originate from structures and mechanisms that are present in the liquid under ambient conditions.