Collisional recombination reaction H+O-2+M->HO2+M: Quantum mechanical study using filter diagonalization

We report the results of calculations for the collisional recombination rate of the reaction H+O-2+M-->HO2+M. This study uses the recently developed quantum mechanical theory of recombination (within the strong collision approximation) based on the flux-flux correlation function analysis [J. Phys. Chem. 99, 12387 (1995)]. The quantum dynamics calculations are based on the new very efficient computational procedure of filter diagonalization [J. Chem. Phys. 103, 10074 (1995)]. This procedure allows one to obtain individual complex eigenenergies and eigenfunctions of a large non-Hermitian matrix representation of the Hamiltonian with an absorbing potential. The computed rates are compared to the Lindemann steady-state approximation result. The latter leads to an overestimation of the rate since it does not take into account the resonance interference effects. This becomes more critical at higher temperatures where many bread high energy overlapping resonances contribute to the rate. (C) 1996 American Institute of Physics.