Measurements and calculations of collisional line broadening and mixing in the Raman spectrum of N[formula omitted] perturbed by CO

Abstract

Measurements in the rotationally-resolved Q branch of the Raman spectrum of the fundamental vibration (v=0→v=1) of N2 perturbed by CO have been conducted at three temperatures, 77, 195 and 298 K, in order to obtain broadening and mixing coefficients for the different rovibrational lines observed. In parallel with these measurements, calculations have also been performed on the system at the same three temperatures to obtain theoretical values for the coefficients. The experiments have been carried out using high-resolution stimulated Raman spectroscopy (SRS), while for the calculations two different approaches have been explored: a quantum dynamical calculation and a parametric one utilizing the energy-corrected sudden (ECS) approximation. Comparison between experiment and calculations show good agreement for both the quantum dynamical and the ECS calculated values. This is, to our knowledge, the first reported experimental determination of collisional line broadening and mixing coefficients in the spectrum of N2 perturbed by CO. We also present a brief comparison with the results of prior calculations and with measurements conducted not long ago in the reverse collisional system (i.e., CO perturbed by N2).