Nitrogen-induced broadening and shift coefficients of rotation–vibrational lines in the fundamental and first overtone bands of HCl and HBr

Abstract We present experimental data on the line pressure broadening and shift coefficients in the fundamental and first vibrational overtone bands of HCl and HBr in mixtures with nitrogen gas at room temperature. Most of the reported spectral line parameters are published for the first time. A satisfactory agreement with the results of relevant previous studies is also demonstrated. The line broadenings are found to be almost independent on the upper state vibrational quantum number. In contrast, the line shifts show a strong dependence on the vibrational excitation of the colliding species. The magnitude of the negative (red) line shifts increases with increasing rotational quantum number J and either reaches a maximum, as in the HCl–N 2 system, or after reaching a maximum begins decreasing again with the further growth of the rotational kinetic energy, as in the HBr–N 2 system.