Self-Broadening and Linestrength in the ν2and ν5Bands of CH3F

Abstract The self-broadening coefficients and the linestrengths of 30 lines in the ν 2 and ν 5 fundamental bands of CH 3 F have been measured at high resolution in the range 1417–1553 cm −1 , using a tunable diode-laser spectrometer. The lineshape parameters were obtained by fitting noncorrelated Galatry and Rautian profiles to the measured shapes of the lines. Both models show good agreement between the self-broadening coefficients derived from the spectra at “low” pressure (0.4 to 3 mbar) and those recorded at “high” pressure (6 to 18 mbar), but feature an overestimation of the dynamical friction parameter. A semiclassical calculation of the self-broadening coefficients, performed by using the main electrostatic interactions only, has provided larger results than the experimental data.