Size and structure of molecular clusters in supercritical water

The type and topology of hydrogen-bonded molecular clusters of water are investigated by the molecular dynamics method for five models of water in supercritical conditions. Small clusters (of the order of 10 molecules) are present in all models, even at densities of less than 0.2g/cm³. When the density increases, a phase transition occurs from vapor-like to fluid-like state. Among small clusters, linear structures are predominant.