Variationally Computed IR Line List for the Methyl Radical CH3

Ahmad Y Adam; Andrey Yachmenev; Sergei N Yurchenko; Per Jensen

doi:10.1021/acs.jpca.9b02919

Variationally Computed IR Line List for the Methyl Radical CH₃

J Phys Chem A. 2019 Jun 6;123(22):4755-4763. doi: 10.1021/acs.jpca.9b02919. Epub 2019 May 28.

Authors

Ahmad Y Adam¹, Andrey Yachmenev^{2

3}, Sergei N Yurchenko⁴, Per Jensen¹

Affiliations

¹ Fakultät für Mathematik und Naturwissenschaften, Physikalische und Theoretische Chemie , Bergische Universität Wuppertal , D-42097 Wuppertal , Germany.
² Center for Free-Electron Laser Science , Deutsches Elektronen-Synchrotron DESY , Notkestraβe 85 , D-22607 Hamburg , Germany.
³ The Hamburg Center for Ultrafast Imaging , Universität Hamburg , Luruper Chaussee 149 , D-22761 Hamburg , Germany.
⁴ Department of Physics and Astronomy , University College London , Gower Street , WC1E 6BT London , U.K.

PMID: 31050423
DOI: 10.1021/acs.jpca.9b02919

Abstract

We present the first variational calculation of a hot-temperature ab initio line list for the CH₃ radical. It is based on a high-level ab initio potential energy surface and dipole moment surface of CH₃ in the ground electronic state. The ro-vibrational energy levels and Einstein A coefficients were calculated using the general-molecule variational approach implemented in the computer program TROVE. Vibrational energies and vibrational intensities are found to be in very good agreement with the available experimental data. The line list comprises 9 127 123 ro-vibrational states ( J ≤ 40) and 2 058 655 166 transitions, covering the wavenumber range up to 10 000 cm^-1 and should be suitable for temperatures up to T = 1500 K.