Rotational relaxation rates in HF and Ar–HF from the direct inversion of pressure broadened linewidths

Self‐ and argon‐broadened HF linewidths have been inverted to obtain state‐to‐state rate constants using the energy corrected sudden (ECS) scaling theory inversion procedure. Both rotation–translation and rotation–rotation rates are presented as a function of vibrational level. We find that rotation–rotation processes are dominant for relaxation in pure HF and that these processes decrease with increasing vibrational excitation of one of the collision partners. We also find that the contribution of rotation–translation mechanisms increases with increasing vibrational excitation.