Ion-Pair Theory of Concentrated Electrolytes. II. Approximate Dielectric Response Calculation

The theoretical program initiated in the preceding paper is continued. The wavelength‐dependent dielectric response function for the “primitive‐model” electrolyte, $\mathrm{\epsilon (k)}$ , is evaluated by means of a self‐consistent torque calculation for ion pairs in an external field. The result is used to obtain the longestranged component of the ion‐atmosphere charge density. The rigorous second‐moment condition on the ion atmosphere then is used to compute crudely the short‐ranged components. Besides the usual lowconcentration terms, the implied free energy [Eq. (76)] and activity coefficient [Eq. (77)] contain negative terms varying with the four‐thirds power of concentration.