  An open question is whether the liquid and glassy phases of water are
thermodynamically distinct or continuous. Here we address this question using
molecular dynamics simulations in comparison with neutron scattering
experiments to study the effect of temperature and pressure on the local
structure of liquid water. From both simulations and experiments, we find that
the liquid structure at high pressure is nearly independent of temperature, and
remarkably similar to the known structure of the high-density amorphous ice
(HDA). Further at low pressure, the liquid structure appears to approach the
experimentally-measured structure of low-density amorphous ice (LDA) as
temperature decreases. These results are consistent with continuity between the
liquid and glassy phases of H$_2$O.
