Temperature dependences of self- and N2-broadened line-shape parameters in the ν3 and ν5 bands of 12CH3D: Measurements and calculations.

This paper presents the results of a spectroscopic line shape study of self- and nitrogen-broadened 12 CH 3 D transitions in the ν 3 and ν 5 bands in the Triad region. We combined five pure gas spectra with eighteen spectra of lean mixtures of 12 CH 3 D and nitrogen, all recorded with a Bruker IFS-125 HR Fourier transform spectrometer. The spectra have been analyzed simultaneously using a multispectrum nonlinear least squares fitting technique. N 2 -broadened line parameters for 184 transitions in the ν 3 band and 205 transitions in the ν 5 band were measured. In addition, line positions and line intensities were measured for 168 transitions in the ν 3 band and 214 transitions in the ν 5 band. We have observed 10 instances of weak line mixing corresponding to K ″=3 A1 or A2 transitions. Comparisons were made for the N 2 -broadening coefficients and associated temperature exponents with corresponding values calculated using a semi-classical Robert Bonamy type formalism that involved an inter-molecular potential with terms corresponding to short- and long-range interactions, and exact classical molecular trajectories. The theoretical N 2 -broadened coefficients are overestimated for high J values, but are in good agreement with the experimental values for small and middle range J values. [ABSTRACT FROM AUTHOR]