A non-equilibrium molecular dynamics algorithm was described for simulating multi-component diffusion within the Stefan-Maxwell framework. The approach developed here allowed for the efficient computation of a full diffusion-coefficient matrix for solutions containing any number of species. Due to the interest in electrolytes, the method was tested by simulating aqueous KCl and NaCl salt solutions in the concentration range of 1 to 4m. The results were in semi-quantitative agreement with experiment and in quantitative agreement with previous Green-Kubo calculations for the potential models. This provided strong evidence that the equilibrium and non-equilibrium methods were correct.

Molecular Dynamics Simulations of Multi-Component Diffusion. 2. Nonequilibrium Method. Wheeler, D.R., Newman, J.: Journal of Physical Chemistry B, 2004, 108[47], 18362-7