The Interaction-Asymptotic Region Decomposition Method in Jacobi Coordinates: Triatomic Reactive Scatterings

The interaction-asymptotic region decomposition (IARD) technique has been proven to be a good solution to the long-standing coordinate problem in reactive scattering calculations. In this work, the IARD technique was further developed using Jacobi coordinates for the interaction region, instead of the previously used hyperspherical coordinates. Although the Jacobi coordinate may not be as optimal as the hyperspherical coordinates for describing the interaction region in reactive scattering processes, it has simpler kinetic operators and provides a more physically intuitive picture. By developing an intermediate interpolation method, which could efficiently transform the overlapped wave functions from the asymptotic regions to the interaction region, the new implementation of the IARD technique for triatomic reactive scatterings is similarly efficient and accurate. The differential cross sections of the H+H₂, and product state-resolved reaction probabilities of the F+HD and¹⁶O+³⁶O₂ reactions, which involve products of extremely low translational energy and are challenging for a single coordinate-based method, were calculated as numerical examples to show the ability of the new method.