The method of Hougen, Bunker, and Johns is developed into a unified theory for molecules with one large amplitude internal motion. Examples show how the Nielsen and Hecht-Dennison transformation formulae and also the Hougen-Bunker-Johns formulae for rigid or semirigid large amplitude bending, inversion, and puckering motions follow as special cases from the theory outlined here. The author believes that this theory can also be useful for molecules with more than one large amplitude internal motion. Treating the trimethylene oxide molecule, an example is given for the calculation of effective mass function of small ring molecules.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry