CHAOTIC EFFECTS IN IR RESONANT MOLECULAR VIBRATIONAL PHOTODESORPTION

In this paper the process of IR resonant molecular vibrational photode sorption, applied to the system CH3F-NaCl, is treated in terms of a si mple two-dimensional (2D) classical model. Desorbing trajectories are shown to undergo a chaotic motion. By using the transport theory in Ha miltonian systems, in the phase space spanned by the coordinates of mo lecule-surface bond (the other coordinate being the intramolecular vib rational excitation), the characteristic bottlenecks, which render IR photodesorption an infrequent event, are located, the rates through th em are computed, and the time evolution of the system is followed up t o all times. A comparison with results obtained from numerical simulat ions, which are shown to be impractical in most of the cases of physic al interest, is presented.