Supercooled water shows two different microscopic configurationsknown as high-density and low-density phase. This is the first experimental evidence of an intriguing theoretical hypothesis to explain the unique and fundamental behaviour of water.
Water is called “supercooled” if it remains liquid below its melting point temperature. Supercooled water is neither a solid nor a liquid, it shows an anomalous behaviour. Supercooled water is a metastable state of matter, that is the dynamic observables slow down in a tremendous way.
One of the possible explanation, hypothesize the existence of two liquid waters: the low-density (LD) and the high-density (HD) water forms. Scientists performed a spectroscopic investigation of supercooled water to measure the fast dynamic of water molecules with unprecedent precision. The experiment measures the water intermolecular vibrations and the structural relaxation process. The analysis of experimental data confirms the coexistence of two local microscopic configurations in water.