We present data on atom-triatomic state-to-state collisional transfer that shows an exponential drop in rate as a function of transferred angular momentum. Earlier data on diatomic molecules may also be interpreted in these terms and we outline an alternative model for rotational transfer based solely on angular momentum. In this model, the exponential drop in probability of transfer as a function of transferred angular momentum results from the convolution of the speed distribution with the radial function for the repulsive intermolecular potential. This interpretation offers the opportunity to obtain parameters of the intermolecular potential directly from spectroscopic experiments. An illustration of this angular-momentum-inversion method is given, yielding the first potential inverted from scattering data.

• Received 12 September 1990

DOI:https://doi.org/10.1103/PhysRevA.43.611