Supercritical fluids at subduction zones: Evidence, formation condition, and physicochemical properties

The special physicochemical properties of supercritical fluids arise fundamentally from their intermediate composition and intermediate degree of polymerization that are distinctive from aqueous fluids or silicate melts. Probing the structure and properties of supercritical fluids, which are required for understanding of their petrological and chemical behavior and geophysical characteristics, relies mainly on in situ spectroscopy, but first-principles molecular dynamics is becoming a potentially powerful alternative approach.