Modelling the far wings of collision-induced translational spectral profiles

By comparing three model spectral profiles to precise line shapes obtained from quantum calculations, we assess the suitability of the various models for describing the far wings of translational collision-induced spectra. A profile obtained based on a generalized Langevin approach can give a better fit to the quantum shape than the widely used Birnbaum-Cohen model; the fit given by the six-parameter extended Birnbaum-Cohen profile proves to be the best of all three functions.