Knowledge Bank

In a recent $publication1$ from our laboratory the observation of the frequency shifts of the quadrupolar components of the collision-induced fundamental band of $H2$ was reported. It was found that for the binary mixtures of para $H2$ (density range 4-10 amagat) with Xe (10--70 amagat) and Kr (10-135 amagat) the quadrupolar components of the band show shifts of $9cm-1$ and $6cm-1$, respectively, toward lower frequency from the corresponding Raman frequencies of the low pressure gas. However, no shift for these components was found for the binary mixtures of para $H2$ (4-10 amagat) with Ar (10-100 amagat). In the present paper similar results have been obtained for the shifts of the quadrupolar components of the band in binary mixtures of normal $H2$ with Xe, Kr, and Ar when a similar range of densities of the gases was used. Further, the overlap profiles obtained by subtracting the synthetic quadrupolar profiles from the experimental profiles for the three binary mixtures were analyzed by a computational procedure using a new line shape which was assumed to consist of two functions, one the Fourier transform of the intercollisional correlation function given by Van $Kranendonk2$ and the other the Fourier transform of the intracollisional correlation function given by Levine and $Birnbaum.3$