Supercooled water: Two phases?

C. Austen Angell states that simulations of a well-studied model of water provide strong support for the coexistence of two distinct metastable liquid-water phases. He states that experiments on supercooled water at negative pressures will be able to confirm this point. One of the more provocative ideas proposed in 1992 on the basis of simulations on the ST2 model of water is that the anomalies are a fallout from the existence of a nearby liquid liquid critical point (LLCP). Some researchers have also used light-scattering techniques to probe pure water contained within two microscopic inclusions. These researchers have cooled the sample in the inclusion to sufficiently low temperatures for liquid water to reach a state of mechanical tension to achieve negative-pressure conditions.