Quantum state-to-state cross sections for atom-diatom reactions: A Chebyshev real wave-packet approach

We describe the implementation of a quantum mechanical method to calculate state-to-state differential cross sections for atom-diatom reactive scattering processes. The key ingredient of this approach is the efficient and accurate propagation of a real scattering wave packet in the Chebyshev order domain, from which the $S$-matrix elements can be extracted. This approach is implemented with Open MP and applied to compute differential and integral cross sections for the direct $\mathrm{H}+{\mathrm{H}}_2$ abstraction reaction and the more challenging $\mathrm{N}\left({}^{2}D\right)+{\mathrm{H}}_2$ insertion reaction.