POTENTIAL-ENERGY SURFACES AND VIBRATIONAL-SPECTRA OF H5O2+ AND LARGER HYDRATED PROTON COMPLEXES
1995 (English)In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 56, no 29, 657-668 p.Article in journal (Refereed) Published
This article presents calculations of the structure, binding energetics, potential energy surfaces, and vibrational spectra of the H5O ion. The 15-dimensional potential energy surface for the seven nuclei in the ionic complex was computed by pointwise ab initio Møller-Plesset second-order perturbation (MP2) calculations, using the correlation-consistent pVTZ basis set augmented with diffuse basis functions on oxygen. The potential energy surface for the proton-transfer mechanism was investigated, and the effects of surrounding water molecules on the proton-transfer potential energy curve was studied. Density functional calculations for the proton-transfer potential surface are compared to the MP2 results. Geometry-optimized structures, binding energies, and harmonic vibrational spectra of H5O and H9O are presented. The energy-minimum structure of H5O using the augmented pVTZ basis set is of C2 symmetry, whereas for H9O, using the TZ2P basis set, it is of C3 symmetry. The H-bonded OH stretching harmonic frequency of H5O is very low, 913 cm−1, whereas for H9O it is 2927 cm−1. The subspace spanned by the hydrogen-bonded OH distance and the OO distance were used in one- and two-dimensional calculations of the anharmonic vibrational spectrum using collocation methods. The coupling of the OH stretch with the OO vibration causes a redshift and the anharmonicity a blueshift of the OH frequency: the resulting fundamental frequency of the H-bonded OH vibration is 1275 cm−1. Zero-point energies of the proton vibration and pathways for exchange of protons within H5O are discussed. © 1995 John Wiley & Sons, Inc.
Place, publisher, year, edition, pages
1995. Vol. 56, no 29, 657-668 p.
IdentifiersURN: urn:nbn:se:liu:diva-115225DOI: 10.1002/qua.560560872ISI: A1995TJ79300070OAI: oai:DiVA.org:liu-115225DiVA: diva2:794256
35th Annual Sanibel Symposium, FEB 25-MAR 04, 1995, PONCE LEON CONF CTR, ST AUGUSTINE, FL