Electrical conductance of cryptate solutions: Comparison between experiments and simulation results

Smart Brownian dynamics have been used to compute the electrical conductanc e of aqueous cryptate chloride solutions; the results are compared to exper imental data. The numerical simulations take into account both direct and h ydrodynamic interactions between ions. Direct interactions are modelled by pairwise soft-core interactions and several interaction potentials are comp ared; hydrodynamic interactions are evaluated by a modified Rotne-Prager te nsor, which can be used even if two particles overlap. It is shown that the experimental data can be interpreted by numerical simulations if the inter action potential between ions contains a short-range attractive contributio n in addition to the Coulomb and the short-range repulsive parts.