1. A theoretical study of vibrational mode coupling in H5O2+
- Author
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Stuart Carter, Joel M. Bowman, Jixin Dai, Xinchuan Huang, and Zlatko Bačić
- Subjects
Water dimer ,Proton ,Chemistry ,General Physics and Astronomy ,Protonation ,Configuration interaction ,Molecular vibration ,Mode coupling ,Potential energy surface ,Physics::Atomic and Molecular Clusters ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,Atomic physics ,Adiabatic process - Abstract
The vibrational mode coupling in the protonated water dimer is investigated by performing two types of quantum calculations of the vibrational levels of H5O2+ and D5O2+, utilizing the OSS3(p) potential energy surface by Ojamae et al. [L. Ojamae, I. Shavitt, and S. J. Singer, J. Chem. Phys. 109, 5547 (1998)]. One is four-dimensional (4D), treating only the central O⋯H(D)+⋯O moiety. Three of the four modes considered, the asymmetric stretch and the two bends, are largely the vibrations of the central proton, while the fourth mode is essentially the O⋯O stretching vibration. The vibrational levels of O⋯H(D)+⋯O are calculated rigorously, as fully coupled (FC), and also in an adiabatic (3+1)D approximation, where the proton asymmetric stretch is treated as adiabatically separated from the other three degrees of freedom. The second set of calculations, designated VCI, is full-dimensional, 15D; it is performed by the code MULTIMODE, which does configuration interaction (CI) calculations using a basis determined ...
- Published
- 2003