New assignments, line intensities, and HITRAN database for CH3OH at 10μm
| Autor: | J.W.C. Johns, Peng Wang, Li-Hong Xu, Linda R. Brown, Isabelle Kleiner, Ronald M. Lees |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Physics
Line positions Database Methanol Torsional modeling Infrared spectroscopy Internal rotation Infrared spectra computer.software_genre Atomic and Molecular Physics and Optics Spectral line symbols.namesake Dipole Fourier transform Excited state symbols HITRAN Physical and Theoretical Chemistry Hamiltonian (quantum mechanics) Ground state Line intensities computer Spectroscopy |
| Zdroj: | Journal of Molecular Spectroscopy. 228:453-470 |
| ISSN: | 0022-2852 |
| DOI: | 10.1016/j.jms.2004.05.017 |
| Popis: | The Fourier transform spectrum of CH 3 OH in the 10 μm region has been re-examined at higher pressure and path length than heretofore, as part of a program to provide comprehensive CH 3 OH spectral data for astrophysical and atmospheric applications. With the increase in spectral sensitivity, it has been possible to assign new torsionally excited ν 12 =1 and ν 12 =2 subbands plus further high- K , ν 12 =0 subbands of the ν 8 CO-stretching band. Upper-state term values have been determined, and have been fitted to J ( J +1) power-series expansions in order to obtain the excited ν 8 substate origins. A variety of weaker subbands from other modes has also been identified in the 10 μm spectrum including ν 12 =0, ν 12 =1, and ν 12 =0←1 torsional subbands of the ν 7 in-plane CH 3 rock, ν 12 =0←1 and ν 12 =0←2 torsional combination subbands of the ν 6 OH bend, and ν 12 =0←2 subbands of the ν 5 symmetric CH 3 bend. Line intensities have been retrieved line-by-line from the spectra. A large set of “unperturbed” ν 8 transitions has been modeled using the same type of multi-parameter effective Hamiltonian employed successfully for the ground state, with inclusion of the intensities of a subset of the stronger ν 8 spectral lines in the fitting in order to obtain appropriate transition dipole terms. Together, a 10 μm methanol database in HITRAN format has been generated. |
| Databáze: | OpenAIRE |
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