A density functional theory formulation of the reaction field model of solvent effects

It is possible to reformulate the reaction field (RF) model of continuum solvent effects, by considering an approximate expression describing the energy changes from one ground state to another, in the frame of density functional theory (DFT). The energy functional for an arbitrary electronic system coupled to a spin‐independent electrostatic external perturbation is used to derive the well‐known Born expression giving the electrostatic component of the solvation energy of an atomic ion. The approximate RF–DFT model is illustrated for a series of representative singly positive and negatively charged atomic ions. A Kohn–Sham (KS)‐like formalism is then proposed to compute solvation energies within a self‐consistent field scheme. The extension of the RF‐DFT model to molecular systems is also outlined. © 1995 John Wiley & Sons, Inc.