Theoretica chimica acta

, Volume 84, Issue 1–2, pp 125–133 | Cite as

Heavy-atom tunneling in cyclobutadiene:Ab initio calculation of the intensities ofa g Raman lines

  • P. Čársky
  • J. Michl


GVB/[5s3p1d/3s1p] calculations were performed on the polarizability surface α(Я1, Я2, Я3) of cyclobutadiene. The threea g coordinates refer to automerization (Я1), symmetric CC stretch (Я2), and symmetric CCH bend (Я3). This surface was used together with the previously obtained variational vibrational wave functions for the calculation of Raman intensities. The calculation predicts comparable intensities for the two split components of the automerization Raman line in an isolated molecule and disagrees with observations on matrix-isolated cyclobutadiene. The disagreement is attributed to the asymmetry of the double-well potential imposed by the effect of the Ar matrix.

Key words

Raman intensities Tunneling Cyclobutadiene Ab initio calculations of polarizabilities Variational calculation of vibrational levels 


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Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • P. Čársky
    • 1
  • J. Michl
    • 2
  1. 1.J. Heyrovský Institute of Physical Chemistry and ElectrochemistryCzechoslovak Academy of SciencesPrague 8Czechoslovakia
  2. 2.Department of Chemistry and BiochemistryUniversity of Colorado at BoulderBoulderUSA

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