Diffusion lengths for both ion pairs and water molecules in ions' first solvation shells are computed via L = √ Dτ , where τ is the average lifetime of the pair of species. This lifetime is evaluated using the correlation function P αβ (t) = H αβ (t)H αβ (0) , where H αβ (t) is one if particles α and β are neighbors at time t and zero otherwise. Two particles are defined as neighbors if they are within a specified cutoff distance, which we take to be the first