The long-time limit is then identified with σ d ++ , σ d --, and σ d +-, respectively. Similar to the overall conductivity, these observables display a straightforward dependence on salt concentration as well as overall mobility. In order to isolate the correlations between like and unlike pairs, we normalize the distinct conductivites by the N-E conductivity which exactly contains these two factors. Furthermore, this representation allows us to obtain insight why to a good approximation the ratio of the ionic conductivity and the N-E conducitivity is constant in the considered range of salt concentrations.