Temperature dependence of CH3I self-broadening coefficients in the ν6 fundamental

Abstract Temperature dependence of methyl iodide self-broadening coefficients in the fundamental ν6 band is evaluated theoretically by the use of a semi-classical and a semi-empirical approaches in the range 200–400 K recommended for HITRAN. In the absence of not-room-temperature measurements, comparisons are performed solely between line-width sets computed by the two methods at some fixed temperatures. Traditional temperature exponents as well as parameters of the recently suggested double power law [JQSRT 2018;217:440-52] (going beyond the considered temperature range) are determined for (J, K)-lines with 0 ≤ J ≤ 70, K ≤ 20 requested by spectroscopic databases. Because of the negligible vibrational dependence, these data can be safely used for other perpendicular and parallel bands studied in atmospheric applications.