13 12 Line positions and intensities for the m12 band of C CH6

Devi, V. M., D. C. Benner, K. Sung, T. J. Crawford, A. W. Mantz, and M. A. H. Smith (2014), 13 12 Line positions and intensities for the m12 band of C CH6, Journal of Molecular Spectroscopy, 301, 28-38.

Ethane 13 12

C CH6 Line positions Line intensities Infrared fundamental Planetary atmospheres High-resolution, high signal-to-noise spectra of a high-purity (99%) mono-substituted 13C-enriched ethane (13C12CH6) in the m12 fundamental band near 12.2 lm region were recorded with a Bruker IFS 125HR Fourier transform spectrometer. The data were obtained for four sample pressures at three different temperatures (130–208 K) using a 20.38-cm long coolable absorption cell. The spectra were fitted simultaneously to retrieve individual line positions and absolute line intensities for 1660 absorption features. A multispectrum nonlinear least squares spectrum fitting technique was employed in the analysis. Constraints were used to fit each pair of doublet components arising from torsional Coriolis interaction of the excited m12 = 1 state with the nearby excited torsional m6 = 3 state. Line positions and absolute line intensities were retrieved by simultaneously fitting the four experimental spectra recorded at three low sample temperatures (130 K, 178 K and 208 K). The measured positions and intensities were determined for the standard reference temperature of 296 K and compared with the predicted values listed in the HITRAN database. Calculated line intensities at each of the measured spectrum temperatures are also provided as supplemental data. Integrated intensities are also reported.