Preliminary analysis of the interacting pentad bands (ν2+2ν4,ν2+ν3,4ν2,ν1+2ν2,2ν1) of CF4 in the 1600 – 1800 cm−1 region

• Published in: Journal of quantitative spectroscopy & radiative transfer 2019-03, Vol.226, p.92-99
• Main Authors: Mattoussi, M., Rey, M., Rotger, M., Nikitin, A.V., Chizhmakova, I., Thomas, X., Aroui, H., Tashkun, S., Tyuterev, Vl.G.
• Format: Article
• Language: English
• Subjects: ab initio; CF4; Infrared spectrum; Line positions and intensities; Mathematical Physics; Physics; Tensorial formalism
• ISSN: 0022-4073; 1879-1352
• DOI: 10.1016/j.jqsrt.2019.01.018

•First line position and line intensity analysis for CF4 in the range 1600–1800 cm−1. Combination of ab initio predictions and high order contact transformations.•Present analysis will be used for future HITRAN updates. The Fourier transform spectrum of CF4 in the 1600–1800 cm−1 was recorded in Reims by using a White-type multi-pass cell to provide a path length of 8.262 m. In the present work, all spectrum analyses and fits were realized using the MIRS software based on tetrahedral tensorial formalism. By combining non-empirical contact transformation Hamiltonians for line positions and ab initio ro-vibrational normal-mode predictions for line intensities, we are able to achieve a simultaneous fit of effective Hamiltonian and dipole moment parameters of several cold and hot bands of CF4. Hamiltonian operator was expanded up to the sixth order for the ground state and for the {ν2+2ν4,ν2+ν3,4ν2,ν1+2ν2,2ν1} pentad. 1831 line positions were fitted to RMS of 1.5X10−3 cm−1. The standard deviation for line intensities for the cold bands {ν2+2ν4,ν2+ν3,4ν2,ν1+2ν2,2ν1} is of 1.1% and of 8% and 5% for the hot band transitions {2ν2+2ν4−ν2,2ν2+ν3−ν2} and {ν2+3ν4−ν4,ν2+ν3+ν4−ν4}, respectively. [Display omitted]