Ab initio SCF calculations on electrostatically solvated molecules using a deformable three axes ellipsoidal cavity

The analytical expression of the free energy of solvation of a molecule interacting with a dielectric continuum through a three axes ellipsoidal cavity is used to derive the SCF equations of such a solvated molecule. In this paper, the shape of the cavity is defined after the principal values of the electronic polarizability tensor. Applied to two sets of rotational isomers (trans and gauche 1,2 difluoroethane, and E and Z N methyl formamide), this method confirms that the electronic structure, the molecular geometry, and the equilibrium constant are influenced by the solvent. The energy of solvation depends strongly on the shape of the cavity although the electronic structure appears to be less influenced by a modification of the geometrical characteristics of the boundary surface at constant volume of cavity. Therefore, the computation of the electronic wave function of a molecule interacting with a solvent by electrostatic and induction forces appears to be quite feasible.