State-to-state three-atom reactive scattering using adiabatic rotation approximations

In this work we explore the applicability of the adiabatic rotation approxi mations to state-to-state quantum reactive scattering for three-body system s within the context of the coupled-channel hyperspherical coordinates meth od. A novel refinement to the adiabatic rotation approximation advocated by :Bowman (Chem. Phys. Lett. 1994, 217, 36) has been obtained by the inclusio n of the asymmetric rotational terms into the Hamiltonian. Within this appr oach, the total Hamiltonian is separated in an exact Hamiltonian for zero t otal angular momentum plus an effective rotational energy term that is adde d to the potential energy surface to form an effective potential on which t he reactive dynamics evolves. Calculations of state-to-state reaction proba bilities, integral and differential cross-sections for the prototypical rea ctions Cl + H-2 and F + H-2 are presented to test their accuracy and comput ational advantages in comparison with exact quantum mechanical calculations .