Outer statistical mechanical model

Recent statistical-mechanical theories [62] and Monte Carlo simulations of the diffuse double layer [63, 64] predict that the potential of the outer Helmholtz plane is generally overestimated in the Gouy-Chapman theory. If this is the case, the potential drop across the inner layer can be even greater, e.g., by c. 15% if a hypernetted-chain approximation is applied to the primitive model of the diffuse layer [12]. 

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