On the nitrogen-induced far-infrared absorption spectra

The rototranslational absorption spectrum of gaseous N 2 is analyzed, considering quadrupolar and hexadecapolar induction mechanisms. The available experimental data are accounted for by using a line-shape analysis in which empirical profiles describe the single-line translational profiles. We thus derive the simple procedure that allows one to predict the N 2 spectrum at any temperature. On the basis of the results obtained for the pure gas, we also propose a procedure to compute the far-infrared spectrum of the N 2 –Ar gaseous mixture. The good agreement between computed and experimental N 2 –Ar data indicates that it is possible to predict the far-infrared absorption induced by N 2 on the isotropic polarizability of any interacting partner.