ExoMol line lists – LXII. Ro-vibrational energy levels and line strengths for the propadienediylidene (C 3 ) in its ground electronic state

Journal article

Improved opacities are needed for modelling the atmospheres and evolution of cool carbon-rich stars and extra-solar planets; in particular, contributions made by the astrophysically important propadienediylidene () molecule need, at a minimum, to be determined using a line list which includes all significant transitions in the energy range of interest. We report variational calculations giving ro-vibrational energy levels and corresponding line strengths for , , and . In the case, we obtain 2166 503 ro-vibrational state energies 2000 cm−1 for the electronic ground state. Comparison with experiment indicates a maximum error of in calculated positions of lines involving an upper state energy 4000 cm−1. For lines with upper state energies 4000 cm−1 to have comparable line-position accuracies, conical intersections would need to be accounted for in an adopted potential energy surface. Line lists and associated opacities are provided in the ExoMol data base (http://www.exomol.com).

Authors: Lynas-Gray, AE; Polyansky, OL; Tennyson, J; Yurchenko, SN; Zobov, NF

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Oxford University Press
• Journal: Monthly Notices of the Royal Astronomical Society
• Volume: 535
• Issue: 2
• Pages: 1439-1448
• Publication date: 2024-10-23
• Acceptance date: 2024-10-22
• DOI: 10.1093/mnras/stae2425
• EISSN: 1365-2966
• ISSN: 0035-8711
• Language: English
• Keywords: molecular data; ISM: molecules; opacity; stars: atmospheres; planets and satellites: atmospheres