Pressure broadening coefficients in the ν6 band of CH3F in collision with He

In this study we report the first measurements of the pressure line broadening coefficients of 219 lines of CH3F in the (P)p, P-R, (R)Q, (P)Q and R-R sub-branches of the nu(6) band (8.5 mu m-spectral region) at room temperature using a high-resolution Fourier transform spectrometer. The collisional line widths are obtained from the non-linear least-square multi-pressure fitting techniques. A Voigt line shape model was used in the present analysis. Measured values are compared with the results of theoretical calculation based on semi-classical formalism of Robert-Bonamy (RB) model with exact isotropic trajectories. Even with a Smith-Giraud-Cooper intermolecular potential model the calculated values show a quite good agreement with experimental results. (C) 2018 Published by Elsevier Inc.