Measurements and calculations of collisional line parameters for Raman lines of CO perturbed by H2

Abstract

Close coupling calculations of line shape parameters have been performed for the first pure rotational Raman S0(j=0−3) lines of CO in an H2 bath. The pressure broadening coefficients obtained are in good agreement with the experimental values recently measured at 77, 180 and 298 K by some of us. The quantum dynamical calculations allow us to also determine line shift and Dicke parameters over a wide range of temperatures (20 to 400 K) for these lines. In addition, acquisitions of Raman spectra of the fundamental vibrational Q branch of CO in H2 have been performed allowing the determination of pressure broadening and line mixing coefficients for the first lines of the band at 77, 195 and 298 K. Based on our calculated pure rotational rate constants, we have also deduced pressure broadening and line mixing coefficients for these rovibrational lines. Theoretical values compare reasonably well with the set of experimental data.