https://doi.org/10.1140/epjd/s10053-023-00643-3
Regular Article – Atomic and Molecular Collisions
The selective role of the orbital angular momentum on the reaction stereo-dynamics
1
Dipartimento di Ingegneria Civile ed Ambientale, Università di Perugia, 06125, Perugia, Italy
2
Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123, Perugia, Italy
Received:
15
November
2022
Accepted:
23
March
2023
Published online:
18
April
2023
This paper reports on the characterization of the stereo-dynamic controlling three different chemi-ionization reactions, recent objective of our study, since they participate to the balance of phenomena occurring in plasma, interstellar medium, planetary atmospheres, flames and lasers. The optical potential, obtained by a phenomenological method and defined in the whole space of the relative configurations of reagents, has been formulated in an accurate and internally consistent way for three different systems. Some cuts of the multidimensional potential, that asymptotically correlate with a specific fine level of the open shell atom and/or with a defined orientation of the molecular reagent, have been exploited in the present study to emphasize crucial features of the collision dynamics along selected entrance channels of the reactions. Consistently, basic quantities determining the topology of the reaction stereo-dynamics have been properly defined, emphasizing in the three cases relevant changes in the microscopic reaction evolution. Much attention focused on the selectivity of the orbital angular momentum, affecting each collision event at any chosen collision energy. It controls the relative weight of two different reaction mechanisms. The direct reaction mechanism is driven by short-range chemical forces, promoting, by direct electron transfer between reagents, a prototypical elementary oxidation reaction. The indirect mechanism, controlled by the combination of long-range chemical and physical forces, can be triggered by a virtual photon exchanged between reagents, promoting a sort of photo-ionization process. Obtained results and emphasized differences appear to be of general interest for many other elementary processes, more difficult to characterize at this level of detail.
T.I. : Atomic and Molecular Data and Their Applications: ICAMDATA 2022.
© The Author(s) 2023
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