Collision complex osculating

Fig. 17. Solid-angle differential cross section for the reaction 0( D) + H OH + H proceeding via the insertion-decomposition pathway. The best fit from the osculating complex model (OCM) is the solid curve which is shown superimposed on the histogrammic representation of the trajectory data. The collision energy is 2 kcal/mol. Arrows indicate the range of scattering angles obtained in the trajectory calculations.

One system is 0( D) with the (v=0,j=l) state of H2, HD, or D2 at a collision energy of 2 kcal/mol. Most reactions proceed via an intermediate complex. An analysis of the differential cross sections by the osculating complex model indicates that the average lifetime of the complex is less than or on the order of a rotational period. 

There is a time regime between the obviously bimolecular and obviously unimolecular pathways which encompasses a short-lived complex that exists for only a fraction of a rotation period. Such species have come to be known as osculating-complexes and are characterized by a somewhat asymmetric c.m. angular distribution that exhibits either a maximum or a minimum in both the forward and backward hemispheres. At low collision energies certain reactions occur via osculating complex mechanism but become... 

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