Classical limit of the distribution of quantum fluctuations in inter- and intramolecular dynamics

A spectrum of final states can be produced in many ways. It can be a bound-bound process as in optical spectroscopy, a bound-continuum process as in photodissociation, or even a continuum-continuum transition as in a scattering experiment. A homogeneously broadened, resolved, spectrum exhibits variations in intensity which, while fully predictable by quantum dynamics, appear to the eye as "fluctuations". A phase space structure in which the statistical properties of such fluctuations can be examined is defined and discussed. In the classical limit, one recovers the results of "surprisal analysis". In the more general case, one obtains an extension to situations where quantal interference effects can be important.