Abstract :
Spatial correlations extend about 10 Å in liquid water at room temperature and atmospheric pressure. We have studied these correlations from a topological point of view. Using a novel, effective hydrogen-bond definition, a graph representation of the hydrogen-bond network has been constructed from molecular configurations, generated by classical molecular dynamics simulation. We have developed a scheme to characterize the local topology in terms of different types of loops and chains of water molecules. From this, a detailed picture of the local topology emerges. A comparison with the predictions of a combinatorial model indicates how the proton ordering in SPC/E water differ from that in a random network.
