Microsecond long atomistic simulation of supercooled water

TL;DR

This study uses a 3-microsecond molecular dynamics simulation of the TIP4P-Ew water model to investigate the relaxation and equilibrium properties of supercooled water below the homogeneous nucleation temperature.

Contribution

It provides evidence that the atomistic TIP4P-Ew water model reaches equilibrium in the supercooled regime before ice nucleation occurs.

Findings

The supercooled TIP4P-Ew water model is at equilibrium before nucleation.

Equilibration times are comparable or longer than crystallization times.

Supports the hypothesis that liquid relaxation occurs prior to ice formation.

Abstract

Supercooled water is a metastable phase of liquid water below the melting temperature. An interesting discussion recently developed on the relationship between crystallization rate and the time scales of equilibration within the liquid phase. Calculations using a coarse grained monatomic model of water, the mW model, suggested that equilibration of the liquid below the temperature of homogeneous nucleation $T_H\approx225$ K is slower than ice nucleation. Here, a 3 $\mu$s long molecular dynamics simulation of the TIP4P-Ew water model is presented to investigate the relaxation properties of an atomistic model in the supercooled region below $T_H$. Evidence is provided that the liquid phase of the TIP4P-Ew model is at equilibrium in the supercooled regime before ice nucleation.