Percolation and clustering in supercritical aqueous fluids

Neutron diffraction data for pure supercritical water and supercritical mixtures of water and 2 are analyzed by using the empirical potential structure refinement Monte Carlo simulation, molecular configurations compatible with the experimental data are recorded. The analysis the distribution functions of water cluster size in these fluids allows the identification of a line, which separates gas-like states from liquid-like ones, in pure supercritical . Solvation of CO2 in supercritical water inhibits cluster percolation, although the radial functions show liquid-like behavior: this is likely to be due to the excess volume localized around the CO2 molecules.