Dynamics of centrifugal barrier complexes close to orbiting

Abstract

Trajectories close to orbiting have been studied for central and various non-central potentials in atom—molecule reactions. The complex formation of K + NaCl is considered as a prototype process. These trajectories move close to the peak of the centrifugal barriers and correspond to the trapped trajectories found by Pollak and Pechukas in bimolecular direct reaction systems. An iteration procedure with rapid convergence for finding trajectories close to orbiting has been developed. It is found that the stability of the trajectory is not strongly affected by the form of the potential and the rotational energy of the diatomic molecule. The atom—diatomic molecule distance can vary up to 10% during a complete molecular rotation. Angular momenta and rotational energies show cyclic variations at low but not at high molecular energies due to Coriolis effects. The relation of bimolecular reactions to periodic orbits is discussed.