Helium diffusion in aqueous sodium chloride solution at high pressures

A molecular dynamic investigation of self-diffusion coefficients of helium and water in aqueous NaCl solution is performed. To understand the nonlinear behavior of the self-diffusion coefficients, a number of structural characteristics (radial distribution functions, hydrogen bond network topology) are calculated. The electrolyte concentration range is discussed in which a local increase in helium self-diffusion coefficient is observed. It is shown that this behavior is caused by a breakdown of the network of hydrogen bonds due to competition between ion positions in the states of solvent-separated and contact pairs.