The H-bonded bridges are very dynamic, they form and break up many times during the trajectory. Therefore, we did not attempt to quantify their average lifetime. Instead, in order to better understand their effect on water diffusion, we investigated the distribution of HB donor-acceptor distances along the trajectory. Figure shows the result for the dominant OH don -OH acc bridge and the case of a single water layer. Here, R 1 and R 2 is the distance between the oxygen of the bridging water and the oxygen atom in OH don and OH acc , respectively. The actual time evolution of R 1 and R 2 are given in Figure ?? of the Supplementary Information. In Figure the range of possible HB bridges according to our definition is shown by the rectangle.