Solvation in high-temperature electrolyte solutions. I. Hydration shell behavior from molecular simulation

The behavior of the first hydration shell of species in solution and its relevant thermophysical properties are studied by molecular dynamics of infinitely dilute NaCl aqueous solutions at high temperature. The ion-induced effects on the water local properties are assessed in terms of the corresponding radial profiles for the local density, the local pressure, the local electric field, the local dielectric constant, and two alternative types of coordination numbers, along the near-critical reduced isotherm. T-r = 1.05 and the supercritical reduced isochore rho(r) = 1.5. Simulation results are discussed in the context of their usefulness in enhancing the understanding and the modeling of supercritical aqueous electrolytes. (C) 1999 American Institute of Physics. [S0021-9606(99)50902-1].