Excited Vibrational States: Semiclassical Self-Consistent-Field and Statistical Considerations
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An overview is presented of recent studies of highly-excited vibrational states using both self-consistent-field (SCF) and statistical descriptions. The SCF scheme is the simplest possible extension of the separable-modes picture, and provides quite adequate characterization of all vibrational levels at relatively low levels of excitation. At higher energies, above the classical threshold for chaos, most SCF states are too strongly mixed for the description to remain valid. These strongly-mixed situations are best described statistically, and we present some results of statistical studies of molecular energy levels and wavefunctions. Even at high energies, however, some SCF-type states mix only very weakly. These states, for which the SCF-type description remains valid, should show strong spectroscopic features in absorbtion from lower states. They will generally be of “extremal-motion” type, meaning that, because all vibrational energy greater than zero-point energy is concentrated in a single mode (or possibly a very few modes), the amplitudes for intramolecular vibrational energy transfer, and therefore for mixing with other SCF states, are very small. It is suggested that such high-energy SCF states have already been seen spectroscopically in species such as ozone and HCN.
KeywordsVibrational Energy Vibrational State Configuration Interaction Transition Moment Tunneling Rate
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- 12.R.B. Gerber and M.A. Ratner, Adv. Chem. Phys., submitted.Google Scholar
- 18.C. E. Porter, Statistical Theories of Spectra: Fluctuations ( Academic, New York, 1965 ).Google Scholar
- 27.H. Romanowski, M.A. Ratner and R.B. Gerber, unpublished.Google Scholar
- 32.N. Moiseyev, Chem. Phys. Lett. 98, 223 (1983).Google Scholar
- 34.D.E. Reisner, P.H. Vaccaro, C. Kittrell, R.W. Field, J.L. Kinsey and H-L Dai, J. Chem. Phys. 77, 575 (1982); D.E. Reisner, R.W. Field, J.L. Kinsey and H-L Dai, J. Chem. Phys. 78, 2817 (1983); E. Abramson, R.W. Field, D Imre, K.K. Innes and J.L. Kinsey, J. Chem. Phys. 83, 453 (1985).ADSCrossRefGoogle Scholar
- 46.L. Gibson, unpublished.Google Scholar
- 47.V. Buch, unpublished.Google Scholar
- 48.H. Romanowski, M.A. Ratner, R.B. Gerber, to be published.Google Scholar
- 50.D. Imre, Ph.D. Thesis, Mass Inst. of Technology, 1985.Google Scholar