Three-vector correlation in statistical reactions: the role of the triatomic parity

Abstract

This article presents a methodology for the determination of the k–j–k′ three-vector correlation assuming a statistical model for atom–diatom reactions; k and k′ are the reagent-approach and product-recoil directions, respectively, and j is the rotational angular momentum of the reagent diatomic. Although the polarization of reagent angular momentum is in most cases negligible, conservation of the triatomic parity imposes a certain polarization for some combinations involving low reagent and product rotational states. Statistical and quantum-mechanical polarization-dependent differential cross sections were calculated for the barrierless D⁺ + H₂(v = 0,j) → HD(v′ = 0,j′) + H⁺ reaction. The agreement between the two is in most cases excellent, confirming the statistical character of the reaction at low and moderate collision energies.