Quantitative atom-atom potentials from rotational tunneling: Their extraction and their use

Rotational tunneling of small molecular groups has been the subject of cons iderable theoretical and experimental activity for several decades. Much of this activity has been driven by the promise of exploiting the extreme sen sitivity of quantum tunneling to interatomic potentials, but until recently , there was no straightforward means by which quantitative information abou t these potentials could be extracted. This review explains how a quantitat ive method, suitable for general application, was developed. It then goes o n to show how this has been used to understand tunneling systems for which no previous satisfactory explanation had been found. The application of the methodology, and its results, to other disciplines is discussed.