However, the NE equation assumes ions do not interact with themselves, and is therefore only exact in the infinite dilution limit. For electrolytes with high salt concentrations, ionic transport shifts from single free charge carriers to clusters of salt nucleating, which has the primary function of scaling down the conductivity by forming neutral clusters. To account for aggregate effect, Grossman et al. reformulated the Nernst-Einstein equation with the assumption that clusters do not interact with each other: 34