  We report a molecular dynamics simulation study of the properties of the
potential energy landscape sampled by a system of water molecules during the
process of generating a glass by cooling, and during the process of
regenerating the equilibrium liquid by heating the glass. We study the
dependence of these processes on the cooling/heating rates as well as on the
role of aging (the time elapsed in the glass state). We compare the properties
of the potential energy landscape sampled during these processes with the
corresponding properties sampled in the liquid equilibrium state to elucidate
under which conditions glass configurations can be associated with equilibrium
liquid configurations.
