Water shows intriguing thermodynamic and dynamic anomalies in the supercooled liquid
state. One possible explanation of the origin of these anomalies lies in the existence of a
metastable liquid-liquid phase transition (LLPT) between two (high and low density) forms of
water. While the anomalies are observed in experiments on bulk and confined water and by
computer simulation studies of different water-like models, the existence of a LLPT in water
is still debated. Unambiguous experimental proof of the existence of a LLPT in bulk …