AbstractExtension of the inhomogeneous continuum solvent model to prolate spheroidal cavity systems in the context of Kirkwood–Westheimer substituent‐reactivity theory is described. Reasonable effects attributable to electrical saturation and electrostriction, which are modeled by relatively simple spatial dielectric functions outside the solute–solvent boundary, may be demonstrated. It is also shown that choices of proper (i.e., nonaveraged) location of the interacting sites and magnitude of substituent dipole moments are comparably important to the quality of theoretical predi