Key points are not available for this paper at this time.
For a model quantum system the distributions of the spacings between adjacent levels in specified intervals of the energy spectrum are fitted by the Brody distribution. This analysis displays for the first time the expected transition from regularity to irregularity, in terms of a smooth increase of the parameter of the Brody distribution from 0 to 1.
Haller et al. (Mon,) studied this question.