An interaction-asymptotic region decomposition method for general state-to-state reactive scatterings

Abstract

A single set of coordinates, which is optimal for both asymptotic product and reactant, is difficult to find in a state-to-state reactive scattering calculation using the quantum wave packet method. An interaction-asymptotic region decomposition (IARD) method was proposed in this work to solve this “coordinate problem.” In the method, the interaction region and asymptotic regions are applied with the local optimal coordinate system, i.e., hyperspherical and corresponding Jacobi coordinates. The IARD method is capable of efficiently and accurately accomplishing a calculation with a grid box for the Jacobi coordinate R extending several hundred bohrs for both reactant and product arrangements. We demonstrate the effectiveness of the IARD method with the reaction of H + HD, which is the simplest direct reaction, and F + HD, which is a typical reaction involving resonances with products of extremely slow translational energy and requires extremely long absorbing potential in all channels.

Orbiting resonances in the F + HD (v = 0, 1) reaction at very low collision energies. A quantum dynamical study

“…All partial waves till J max =18 were considered and the propagation was extended in 150 sectors up to 18 a 0 . As sometimes stressed in the literature, [28,59] convergence must be carefully checked when performing calculations for this reaction at low energies. The parameters reported in this article were sufficient to yield cumulative reaction probabilities at J = 0 converged to better than 0.07% at the lowest total energies.…”

Advances and New Challenges to Bimolecular Reaction Dynamics Theory

“…Initial state-specific information is extracted by overlapping with asymptotic states after the WPs are propagated to the asymptotic regions. These different state-to-state approaches to overcoming the “coordinate problem” have been extensively discussed in a recent review, supplemented by some further improvements. , For atom–diatom problems, the hyperspherical coordinates allow three arrangement channels to be treated equally, which is particularly important for X 3 type systems where the three channels are identical. This widely used coordinate system in TIQM treatments has recently been implemented in a WP framework .…”

Observation of the geometric phase effect in the H+HD→H2+D reaction below the conical intersection

“…Here we report a high-resolution CMB study on the H+HD → H 2 +D reaction at the collision energy of 2.28 eV, corresponding to 2.50 eV in total energy, or 0.25 eV below the CI. In addition, we carry out accurate adiabatic quantum mechanical time-dependent wave packet calculations with and without considering the GP effect in hyperspherical coordinates to investigate the role of GP on this reaction [37][38][39] . The GP effect is analyzed by calculating the time-independent scattering wave functions at 2.28 eV in hyperspherical coordinates.…”