Scattering matrix approach to the dissociative recombination of HCO{sup +} and N{sub 2}H{sup +}

Journal Article · Mon Apr 28 04:00:00 EDT 2014 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4871982· OSTI ID:22253021

Fonseca dos Santos, S.; Douguet, N.; Orel, A. E. ^[1]; Kokoouline, V. ^[2]

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1. Department of Chemical Engineering and Material Sciences, University of California, Davis, California 95616 (United States)
2. Department of Physics, University of Central Florida, Florida 32816 (United States)

We present a theoretical study of the indirect dissociative recombination of linear polyatomic ions at low collisional energies. The approach is based on the computation of the scattering matrix just above the ionization threshold and enables the explicit determination of all diabatic electronic couplings responsible for dissociative recombination. In addition, we use the multi-channel quantum-defect theory to demonstrate the precision of the scattering matrix by reproducing accurately ab initio Rydberg state energies of the neutral molecule. We consider the molecular ions N{sub 2}H{sup +} and HCO{sup +} as benchmark systems of astrophysical interest and improve former theoretical studies, which had repeatedly produced smaller cross sections than experimentally measured. Specifically, we demonstrate the crucial role of the previously overlooked stretching modes for linear polyatomic ions with large permanent dipole moment. The theoretical cross sections for both ions agree well with experimental data over a wide energy range. Finally, we consider the potential role of the HOC{sup +} isomer in the experimental cross sections of HCO{sup +} at energies below 10 meV.

• OSTI ID: 22253021
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 16 Vol. 140; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ACCURACY
CALCULATION METHODS
CROSS SECTIONS
DIPOLE MOMENTS
ISOMERS
MEV RANGE
MOLECULAR IONS
QUANTUM MECHANICS
RECOMBINATION
RYDBERG STATES
SCATTERING