Aravindan Semparithi (a) and Srihari Keshavamurthy (a,b)

(a) Department of Chemistry, Indian Institute of Technology, Kanpur, India 208 016, and
(b) Institut fur Theoretische Physik, Universitat Regensburg, 93040 Regensburg, Germany

We study the intramolecular dynamics and highly excited eigenstates of CDBrClF and CF$_{3}$CHFI motivated by recent experiments[1]. The effective spectroscopic Hamiltonians employed in our work, determined by a fit to the experimental spectra, provide an opportunity to study the classical-quantum correspondence for three degrees of freedom systems. In particular, for both the molecules there are nine strong anharmonic resonances coupling the CD/CH stretch, two CD/CH bends and the CF stretch modes. Recently developed techniques of parametric variations[2] allow us to understand the nature of the highly excited eigenstates without recourse to the Poincare surface of sections. We find a fair degree of localization at such high levels of excitations indicating deviations from ergodicity. Insights into the intramolecular dynamics from specific initial states, for instance high overtone states of the CD and CH stretch, are gained by using the wavelet based local frequency analysis[3]. Combined with the intensity-level velocity correlator[4] information regarding the important resonances and possible multidimensional effects on the dynamics can be obtained.

References

[1] A. Beil, H. Hollenstein, O. L. A. Monti, M. Quack, J. Stohner, J. Chem. Phys. 113, 2701 (2000);
J. Pochert, M. Quack, J. Stohner, M. Willeke, J. Chem. Phys. 113, 2719 (2000).
[2] A. Semparithi, V. Charulatha, S. Keshavamurthy, J. Chem. Phys. 118, 1146 (2003).
[3] C. Chandre, S. Wiggins, T. Uzer, Physica D, 181, 171 (2003);
L. V. Vela-Arevalo, S. Wiggins, Int. J. Bifur. Chaos 22, 1359 (2001).
[4] S. Keshavamurthy, N. R. Cerruti, S. Tomsovic, J. Chem. Phys. 117, 4168 (2002).