Non-adiabatic molecular dynamics simulations of non-charge-transfer and charge-transfer scattering in H⁺ +CO₂ at E_Lab=30 eV

The H⁺ +CO₂ reaction at high energies is relevant in atmospheric chemistry, astrophysics, and proton cancer therapy research. Therefore, we present herein a complete investigation of H⁺ +CO₂ at E_Lab=30 eV with the simplest-level electron nuclear dynamics (SLEND) method. SLEND describes nuclei via classical mechanics and electrons with a single-determinantal Thouless wavefunction. The 3402 SLEND conducted simulations from 42 independent CO₂ target orientations provide a full description of all the reactive processes and their mechanisms in this system: non-charge-transfer scattering (NCTS), charge-transfer scattering (CTS), and single C=O bond dissociation; all this valuable information about reactivity is not accessible experimentally. Numerous details of the projectile scattering patterns are provided, including the appearance and coalescence of primary and secondary rainbow angles as a function of the target orientation. SLEND NCTS and CTS differential cross sections (DCSs) are evaluated in conjunction with advanced semi-classical techniques. SLEND NCTS DCS agrees well with its experimental counterpart at all the measured scattering angles, whereas SLEND CTS DCS agrees well at high scattering angles but less satisfactorily at lower ones. Remarkably, both NCTS and CTS SLEND DCSs predict the primary rainbow angle signatures in agreement with the experiment.