A Note on CH3OD Spectra, Ground-State Energies and FIR Laser Assignments
Author: Lees, R.M.
Source: International Journal of Infrared and Millimeter Waves, Volume 21, Number 11, November 2000 , pp. 1787-1805(19)
Abstract:Literature data on the CO-stretching and the ground-state torsion-rotation spectra of the CH_3OD isotopic species of methanol have been exploited to extrapolate the ground-state energies to higher J through use of ground-state combination differences derived from the CO-stretching wavenumbers. In particular, the J-dependence has been extended and better defined for the difficult |K| = 0 to 2 E energy level sequences, which are strongly affected by molecular asymmetry. The pattern of the J-dependence is found to be qualitatively well reproduced by a simple 11 × 11 Hamiltonian model incorporating ΔK = ±1 and ±2 off-diagonal asymmetry matrix elements. The results suggest partial reassignment of certain CO-stretching subbands, and the K = 8 and 9 A subbands have been newly identified through clues from reported far-infrared laser (FIRL) emission. Transition combination loops support a number of FIRL line assignments previously proposed, but show that the FIRL system pumped by the 9R(4) CO_2 line must be reassigned.
Document Type: Regular Paper
Affiliations: Department of Physics, University of New Brunswick, Fredericton, N.B., Canada E3B 5A3
Publication date: 2000-11-01