Theoretical calculation of self-broadening coefficients for the ν5 band of methyl chloride at various temperatures

•We modeled self-broadening coefficients of the ν5 band of methyl chloride.•We performed semi-classical calculations at various temperatures.•We compared our calculation at 296 K to measurements obtained previously.•Temperature dependence exponents have been retrieved.•J- and K-rotational dependencies have been studied.

Self-broadening coefficients of transitions belonging to the ν5 band of methyl chloride have been calculated using a semi-classical model based on the Anderson-Tsao-Curnutte (ATC) theory, including some improvements proposed by Robert and Bonamy. The calculations show the predominance of the dipole-dipole interaction. To better match the experimental measurements performed at room temperature in our previous work, a cut-off of the intermolecular distance has been used. The rotational J and K dependencies of the calculated self-broadening coefficients have been clearly observed and are consistent with our previous measurements.The calculations of the self-broadening coefficients have been performed at various temperatures of atmospheric interest between 200 and 296 K in order to deduce the temperature exponent of the self-widths of CH3Cl.