High-Energy Quantum Dynamics of the ¹⁵N + o-¹⁴N¹⁴N Rovibrational Activation and Isotope Exchange Processes

We report full quantum reaction probabilities, computed within the framework of time-independent quantum mechanics using hyperspherical coordinates, for the ¹⁵N + ¹⁴N¹⁴N inelastic and reactive collision processes, restricted to total angular momentum J = 0, for kinetic energies up to 4.5 eV. We take advantage of the nonzero (i = 1) nuclear spin of ¹⁴N, leading to the existence of two nuclear spin isomers of ¹⁴N¹⁴N, namely, ortho- and para-¹⁴N¹⁴N, to restrict the study to the ortho molecular nitrogen species, with even rotational quantum number j = 0, 2, ... states. Specifically, we start with diatomic reagents ortho-¹⁴N¹⁴N in the initial rotational state j = 0. A comparison with similar works previously published by other groups using time-dependent wave packet and quasi-classical trajectory methods for the ¹⁴N + ¹⁴N¹⁴N fully symmetric collision is given. We find that reactive processes ¹⁵N + ¹⁴N¹⁴N involving atom exchange do not happen for collision energies less than 2.2 eV. Collisions at energies of around 2.0 eV are most effective for populating reactants' rovibrational states, that is, for inelastic scattering, whereas those at energies close to 5.0 eV yield a newly formed ¹⁴N¹⁵N isotopologue in a wide variety of excited vibrational levels.