Dispersion Stabilization of Solvated Electrons and Dipole-Bound Anions

It has long been assumed that stability of “solvated electrons” and dipole-bound anions results primarily from the static Coulomb interaction of an excess electron with charge distribution of the neutral molecular host. Our results indicate, however, that the dispersion interaction between the loosely bound electron and the neutral molecular host is as important as the static Coulomb stabilization. A perturbation scheme is designed to analyze physically meaningful components of electron binding energy, and highly correlated electronic structure results are presented for dipole-bound anions and solvated electrons in the (HF)n clusters (n ) 2, 3). The vertical electron detachment energy for (HF)3 was found to be 0.63 and 0.21 eV for the solvated electron and dipole-bound anion, respectively. The equilibrium zigzag geometrical structure of the dipole-bound anion differs drastically from the cyclic C3h structure of the neutral trimer.