Pair correlation functions and the structure of the electric double layer

The inhomogeneous Ornstein-Zernike equation for the pair correlation functions of an inhomogeneous electrolyte is solved numerically using the Lovett-Mou-Buff-Wertheim equation to relate pair and singlet functions and using the mean spherical approximation to close the Ornstein-Zernike equation. Despite the fact that the pair correlation functions can be unphysical, the resulting singlet density and charge profiles are as good as those obtained from the more complex hypernetted chain approximation and are in excellent agreement with computer simulations. In particular, the layering in the counter-ion profile and the rapid increase in the potential found at large electrode charge found in the simulations, is observed. © 1989.