The shifts of the spectral lines <i>P</i>(4)-<i>R</i>(6) of the fundamental vibration-rotation band of hydrogen fluoride caused by the presence of carbon dioxide were measured. The pattern followed by these shifts in the -R branch was the same as that found by Jaffe et <i>al</i>., for the case of the 1-0 band of HF broadened by krypton. Data were available for only the R branch. The shifts, however, were smaller than those produced by krypton. A new approach to the application of the equivalent-width method for measuring spectral-line width was developed. The half-widths of the CO<sub>2</sub>-broadened lines of the 1-0 band of HF decreased sharply and monotonically as functions of the |<i>m</i>|. The variation followed very closely that reported by Babrov for the 1-0 band of HCl broadened by CO<sub>2</sub>. The line shapes were investigated for the lines which could be corrected for instrumental broadening. The effect of the CO<sub>2</sub> broadener upon the line shape seems to be to flatten the peak and to elevate the wings. The Lorentz exponent, η, decreased from 2.00, for the narrowest lines, to 1.85 for the widest lines investigated. Experimental evidence was obtained in support of the assumption that line intensities are dependent on only the amount of the absorber present.
B. M. SHAW and R. J. LOVELL, "Foreign-Gas Broadening of HF by CO2," J. Opt. Soc. Am. 59, 1598-1601 (1969)