Structures and binding energies of O2−·H2O and O2·H2O

Abstract

High-level ab initio calculations are employed to calculate the minimum energy structures for the O₂⁻·H₂O and O₂·H₂O complexes, with QCISD/aug-cc-pVTZ being the highest level used for the optimizations. Single-point RCCSD(T)/aug-cc-pVQZ calculations are then employed. The anion is found to have a very flat potential energy surface, with the molecule likely to be performing large-amplitude motion at the zero-point energy level. The neutral species is found to be of C_s symmetry and very weakly bound. The vertical and adiabatic electron affinities of the O₂·H₂O complex are calculated, with our best value for the adiabatic electron affinity being 1.22 ± 0.05 eV. Our best value for the binding energies, D_e, are 7116 cm⁻¹ and 126 cm⁻¹ for O₂⁻·H₂O and O₂·H₂O, respectively.