Quantum stereodynamics of four-atom reactions: theory and application to H2+OH↔H2O+H

This article presents a theoretical quantum method for the description of the stereo- dynamics of four-atom reactions of the type AB(vAB, jAB)+CD(vCD, jCD)↔ABC(v1′, v2′, v3′, j′)+D. The method is based on density matrix techniques and angular momentum algebra, and requires knowledge of the scattering matrix. Reagents and products are treated on an equal footing, and the reaction stereodynamics can be analysed either in the rotational polarisation or in the molecular polarisation representation. The formalism is applied to the H2(0, jH2)+OH(0, jOH)↔H2O(0, 0, 0, 0)+H reaction at zero total angular momentum and reveals state-specific correlations between the polarisations of the diatomic molecules, their approach or recoil directions, and the reaction probability.