Room temperature self- and H2-broadened line parameters of carbon monoxide in the first overtone band: Theoretical and revised experimental results. (December 2017)

• Record Type: Journal Article
• Authors: Esteki, Koorosh; Predoi-Cross, Adriana; Povey, Chad; Ivanov, Sergey; Ghoufi, Aziz; Thibault, Franck; Smith, Mary Ann H.
• Is Part Of: Journal of quantitative spectroscopy & radiative transfer. Volume 203(2017)
• Page Start: 309
• Page End: 324
• Publication Date: 2017-12
• Subjects: Carbon monoxide -- CO widths -- CO shifts -- H2 -- Hydrogen -- Infrared spectra -- Line mixing -- Spectral line shapes -- Speed dependence; Spectrum analysis -- Periodicals; Radiation -- Periodicals; Analyse spectrale -- Périodiques; Rayonnement -- Périodiques; Radiation; Spectrum analysis; Periodicals; 543.0858
• DOI: 10.1016/j.jqsrt.2017.04.008
• Languages: English
• ISSNs: 0022-4073

Abstract

Abstract: Lorentz self- and H2 -broadened half-width and pressure-induced shift coefficients, line mixing coefficients as well as line center positions and intensities were obtained using a nonlinear least square fitting technique for 48 (P(24) to R(23)) ro-vibrational transitions belonging to the first overtone (2←0) band of 12 C 16 O at room temperature. All spectra in the 4146 to 4332 cm −1 spectral interval were fitted simultaneously employing four line shape functions: the Voigt, Speed Dependent Voigt, Rautian and Speed Dependent Rautian profiles. The collisional line mixing effect has been observed and investigated as an asymmetry in the analyzed line profiles. A semi-empirical Exponential Power Gap Law method was used to estimate the self- and H2 -broadening coefficients and the collisional line mixing parameters. Additionally, a classical approach was applied to calculate the half-width coefficients of transitions in the 2←0 band for carbon monoxide broadened by H2 and for pure CO. The classical approach based on a simple computational method, ensures the molecular motion is correctly characterized in 3 dimensions. The calculations used vibrationally independent intermolecular interaction potentials. The variation of CO half-width coefficients with rotational quantum number J≤24 was computed and compared with measurements. The agreement between the theoretical broadening coefficients is better for pure CO rather than for the CO-H2 system. Highlights: Self- and H2 -broadened line parameters for transitions in the 2←0 band of CO at 298 K are reported. Line intensities, pressure shifts, line mixing and speed dependence parameters are presented. Calculations of self- and H2 -broadening coefficients of CO using classical impact theory are included.