The dissociative recombination (DR) process of and molecular ions with free electrons has been studied at the heavy-ion storage ring CRYRING (Manne Siegbahn Laboratory, Stockholm University). The absolute cross sections for DR of and in the collision energy range 0.001–1 eV are reported, and thermal rate coefficients for the temperature interval from 10 to 2000 K are calculated from the experimental data. The absolute cross section for agrees well with earlier work and is about a factor of 2 larger than the cross section for The dissociative recombination of is dominated by the product channels and while the DR of mainly results in Ab initio direct dynamics simulations, based on the assumption that the dissociation dynamics is governed by the neutral ground-state potential energy surface, suggest that the primary product formed in the DR process is The ejection of the H atom is direct and leaves the molecule highly vibrationally excited. A fraction of the excited ammonia molecules may subsequently undergo secondary fragmentation forming It is concluded that the model results are consistent with gross features of the experimental results, including the sensitivity of the branching ratio for the three-body channel to isotopic exchange.
Dissociative recombination of and ions: Storage ring experiments and ab initio molecular dynamics
J. Öjekull, P. U. Andersson, M. B. Någård, J. B. C. Pettersson, A. M. Derkatch, A. Neau, S. Rosén, R. Thomas, M. Larsson, F. Österdahl, J. Semaniak, H. Danared, A. Källberg, M. af. Ugglas, N. Marković; Dissociative recombination of and ions: Storage ring experiments and ab initio molecular dynamics. J. Chem. Phys. 22 April 2004; 120 (16): 7391–7399. https://doi.org/10.1063/1.1669388
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