https://doi.org/10.1140/epjd/e2016-70124-7
Regular Article
Higher lying resonances in low-energy electron scattering with carbon monoxide*
1 Department of Chemistry, North Orissa
University, 757003
Baripada, Odisha,
India
2 Department of Physics and Astronomy,
University College London, Gower
St., WC1E 6 BT
London, UK
3 Department of Mathematics,
Scottish Church College, 1
& 3 Urquhart Sq, 700
006
Kolkata,
India
a
e-mail: j.tennyson@ucl.ac.uk
Received:
22
February
2016
Received in final form:
21
May
2016
Published online:
6
October
2016
R-matrix calculations on electron collisions with CO are reported whose aim is to identify any higher-lying resonances above the well-reported and lowest 2Π resonance at about 1.6 eV. Extensive tests with respect to basis sets, target models and scattering models are performed. The final results are reported for the larger cc-pVTZ basis set using a 50 state close-coupling (CC) calculation. The Breit-Wigner eigenphase sum and the time-delay methods are used to detect and fit any resonances. Both these methods find a very narrow 2Σ+ symmetry Feshbach-type resonance very close to the target excitation threshold of the b 3Σ+ state which lies at 12.9 eV in the calculations. This resonance is seen in the CC calculation using cc-pVTZ basis set while a CC calculation using the cc-pVDZ basis set does not produce this feature. The electronic structure of CO− is analysed in the asymptotic region; 45 molecular states are found to correlate with states dissociating to an anion and an atom. Electronic structure calculations are used to study the behaviour of these states at large internuclear separation. Quantitative results for the total, elastic and electronic excitation cross sections are also presented. The significance of these results for models of the observed dissociative electron attachment of CO in the 10 eV region is discussed.
© The Author(s) 2016. This article is published with open access at Springerlink.com
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