Dissociative Electron Attachment to the HNC<sub>3</sub> Molecule
ORAL
Abstract
Dissociative electron attachment (DEA) to the HNC3 is modeled theoretically using a first-principles approach. In HNC3 + e- collisions, there is a low-energy resonance, which has a repulsive character along the H + NC3 coordinate and becomes a bound electronic state of the HNC-3 anion near the equilibrium of HNC3. The anion state dissociates without a potential barrier toward C3N- + H. The cross section and the rate coefficient of the process are computed. The obtained rate coefficient at low temperatures is 5 × 10-9 cm3/s at 300 K. Such a value of the DEA rate coefficient makes the DEA process three orders of magnitude more efficient at producing negative molecular ions in the interstellar space than the radiative electron attachment (REA). It is suggested that negative molecular carbon-chain ions, observed in the interstellar medium, are produced by DEA rather than REA.
*V. K. and J. F. acknowledge support from the US National Science Foundation, Grants No. 2409570 and No. 2303895, respectively. The study was also partially supported by the Transatlantic Mobility Program and Chateaubriand Fellowship of the Office for Science and Technology of the Embassy of France in the United States, Programme National "Physique et Chimie du Milieu Interstellaire" (PCMI) of CNRS/INSU, the program "Accueil des chercheurs ´etrangers" of CentraleSup´elec and from French State aid under France 2030 (QuanTEdu-France) bearing the reference No. ANR- 22-CMAS-0001 and PEPR—SPLEEN Plasma-N-Act.
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Publication:Aubin, E.; Loison, J.-C.; Ayouz, M.; Forer, J.; Kokoouline, V. Dissociative Electron Attachment to the HNC₃ Molecule, Physical Review Letters, accepted 9 January 2026. DOI: 10.1103/mc31-kbnf
