Classical trajectory study of vibration-rotation interaction in highly excited triatomic molecules

Abstract

For two qualitatively different model triatomic molecules, SO2 and "bent equilibrium OCS," classical trajectory calculations of the rotational and vibrational motion are presented for microcanonical ensembles of initial conditions at 35% to 85% of a bond dissociation energy. At the higher energies, many of the trajectories exhibit substantial intramolecular vibrational-rotational energy transfer (IVRET), which has a significant effect on the geometry of rotational motion including in some cases, a transition between the two types of stable asymmetric top motion. IVRET is caused principally by centrifugal interactions, and in "bent OCS," it is dominated by a 2:1 resonance. The rotational motion of about half of the high energy SO2 trajectories is essentially statistical, but bent OCS never undergoes statistical IVRET. © 1985 American Institute of Physics.