Theoretical study of anion-molecule interactions: H^- + HF → H₂ + F^-

We present results of ab initio multiconfigurational SCF (MCSCF), fourth-order perturbation theory MBPT(4), and coupled-cluster CCSD(T) electronic structure simulations on the ground-state H^- + HF → H^-HF → H₂F^- → H₂ + F^- potential energy hypersurface. Structures, energetics, and local harmonic vibrational frequencies are included in this study. The H₂F^- ion-molecule complex is found to be linear; the anticipated H^-HF complex is found to be an unstable inflection point on the surface, (i.e., no bound minimum corresponding to H^- bound to an HF moiety exists). Vertical detachment at the F^-H₂ complex geometry to produce neutrals in ²Σ and ²Π states is also examined.