Semi-empirical calculation of 12CH3D-H2 broadening coefficients and their temperature-dependence exponents for rovibrational lines in parallel bands. (May 2019)

• Record Type: Journal Article
• Authors: Dudaryonok, A.S.; Lavrentieva, N.N.; Buldyreva, J.
• Is Part Of: Journal of quantitative spectroscopy & radiative transfer. Volume 229(2019)
• Page Start: 157
• Page End: 165
• Publication Date: 2019-05
• Subjects: Monodeuterated methane -- H2-broadening coefficients -- Temperature exponents -- Semi-empirical calculation -- Planetary atmosphere; Spectrum analysis -- Periodicals; Radiation -- Periodicals; Analyse spectrale -- Périodiques; Rayonnement -- Périodiques; Radiation; Spectrum analysis; Periodicals; 543.0858
• DOI: 10.1016/j.jqsrt.2019.03.008
• Languages: English
• ISSNs: 0022-4073

Abstract

Highlights: Calculations of CH3 D-H2 line widths for large ranges of quantum numbers. Theoretical evaluation of temperature-dependence exponents for line widths. Line-lists of collisional broadening parameters in R-P-Q-branches of parallel bands. Abstract: Hydrogen-broadening coefficients and their temperature-dependence exponents for 12 CH3 D ( J, K ) lines in the parallel (Δ K = 0) ν3 band are computed by a semi-empirical method employing analytical Anderson-type expressions with a few-parameter correction factor introduced to account for various deviations from Anderson's theory approximations. On the basis of experimentally observed J -dependences of line widths, this correction factor is taken in the traditional two-parameter form, and the parameters are determined from fits on some room-temperature measurements. After validation by comparison with available experimental data, the calculations are done for extended ranges of rotational quantum numbers (0 ≤ J ≤ 70, 0 ≤ K ≤ 20) typically requested for spectroscopic databases. To get the temperature-dependence exponents, computations with the room-temperature parameters' values are repeated for various temperatures in the room-temperature containing range 200–400 K recommended for HITRAN and least-squares fit procedures are applied. Detailed P-Q-R-line lists are provided. With negligible vibrational dependence of CH3 D line widths, these data can be also employed for other A1 -type bands.