  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.
