1. Analysis of high temperature ammonia spectra from 780 to 2100cm−1
- Author
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Zobov, N.F., Shirin, S.V., Ovsyannikov, R.I., Polyansky, O.L., Yurchenko, S.N., Barber, R.J., Tennyson, J., Hargreaves, R.J., and Bernath, P.F.
- Subjects
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AMMONIA spectra , *FOURIER transform spectroscopy , *EMISSION spectroscopy , *VIBRATIONAL spectra , *HAMILTONIAN systems , *PERTURBATION theory , *INFRARED spectroscopy - Abstract
Abstract: A recently-recorded set [Hargreaves et al., Astrophys. J., in press] of Fourier transform emission spectra of hot ammonia is analyzed using a variational line list. Approximately 3350 lines are newly assigned to mainly hot bands from vibrational states as high as v 2 =2. 431 new energy levels of these states are experimentally determined, considerably extending the range of known rotationally-excited states. Comparisons with a recent study of high J levels in the ground and first vibrational states [Yu et al., J. Chem. Phys., 133 (2010) 174317] suggests that while the line assignments presented in that work are correct, their energy level predictions suffer from problems associated with the use of very high-order perturbation series in the effective Hamiltonian. It is suggested that variational calculations provide a more stable method for analyzing spectra involving highly-excited states of ammonia. [Copyright &y& Elsevier]
- Published
- 2011
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