Molecular dynamics simulation of the limiting conductance of NaCl in supercritical water

We report molecular dynamics calculations of the ionic mobility and limiting conductance of NaCl in supercritical water as a function of density along an isotherm 5% above the critical temperature. The number of hydration water molecules around ions is found to dominate the behavior of the limiting conductance in the higher-density region while the interaction between the ions and hydration water molecules is found to dominate in the lower-density region. The different effects in the lower- and higher-density regimes lead to different slopes for the limiting conductance as a function of density in the two regimes.