Quantum dynamics of the ¹⁸O + ³⁶O₂ collision process

Abstract

We report full quantum cross sections and rate constants for the ¹⁸O + ³⁶O₂ → ³⁶O₂ + ¹⁸O collision process. This constitutes to the best of our knowledge the first dynamical study of the ¹⁸O¹⁸O¹⁸O system, with three identical ¹⁸O oxygen atoms. We emphasize the comparison with the ¹⁶O + ³²O₂ collision as this latter presents the exact same features as the one treated here, except the consistent change of mass for all three atoms. We find very similar behaviors in the cross sections, and we confirm that the rates are faster when three identical nuclei are involved. In particular, we cannot dynamically study this system with classical trajectory methods, and we have to include properly the indistinguishability of the three ¹⁸O nuclei; however, we note some slight differences with the ¹⁶O¹⁶O¹⁶O benchmark system, and we focus our analysis on their origin.