10.1021/ja049801i.s001 Xinchuan Huang Xinchuan Huang Bastiaan J. Braams Bastiaan J. Braams Stuart Carter Stuart Carter Joel M. Bowman Joel M. Bowman Quantum Calculations of Vibrational Energies of H<sub>3</sub>O<sub>2</sub><sup>-</sup> on an ab Initio Potential American Chemical Society 2004 messenger experiments 200 cm vibrational energies H 3 O 2 MULTIMODE energy surface oxygen atoms hydroxyl groups quantum Calculations Vibrational Energies hydrogen atom ab Initio 2004-04-28 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Quantum_Calculations_of_Vibrational_Energies_of_H_sub_3_sub_O_sub_2_sub_sup_sup_on_an_ab_Initio_Potential/3341656 We report a full-dimensional potential energy surface for H<sub>3</sub>O<sub>2</sub><sup>-</sup>, based on fitting 66,965 ab initio electronic energies. A major feature of this potential is a barrier of roughly 200 cm<sup>-1</sup> to internal rotation of the two hydroxyl groups about a line connecting the two oxygen atoms and the bridging hydrogen atom. The potential is used in calculations of vibrational energies, performed with the “Reaction Path” version of the code “MULTIMODE”. The results are compared to recent infrared messenger experiments and are used to propose interpretations of the experimental results.