Hidden Slow Dynamics in Water

It is well known that the structural and dynamical properties of water are of central importance for life on our planet. However, despite this knowledge its structural and dynamical properties are still far from fully understood. In this Letter we show for the first time that water exhibits an anomalously slow relaxation process, which is about 4 orders of magnitude slower than the viscosity-related structural main relaxation. This slow Debye-like process has previously only been observed in monoalcohols and more recently also in polyalcohols, and due to its slowness it is generally believed to be caused by some kind of collective motion of hydrogen-bonded structures. The new finding has important structural and dynamical implications for water.