Activation free dielectric continuum model

Considering that ion transfer is associated with the penetration of water into the organic phase and local deformations of the interface, it is not surprising that conventional continuum dielectric models are not successful in describing this process. Not only is the free energy of transfer incorrectly predicted but, more importantly, the model does not yield the activation barrier. The continuum model was also shown to fail in describing ion transport across membranes. 

Simple electrostatic models can be used to interpret the activity coefficients of polar molecules in terms of just three parameters a radius, the dipole moment of the solute, and the dielectric constant of the solvent. The continuum model of the solvent can be used to deduce a value for the free energy of solvation of a spherical molecule of radius r containing a point dipole at its center. The value obtained by Kirkwood from electrostatic theory is... 

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