Expressions for the singular flux operator eigenfunctions and eigenvalues are given in terms
of the Dirac δ-function representable as a localized Gaussian wavepacket. This functional
form enables computation of the cumulative reaction probability N (E) from the wavepacket
time-correlation functions. The Gaussian based form of the flux eigenfunctions, which is not
tied to a finite basis of a quantum-mechanical calculation, is particularly useful for
approximate calculation of N (E) with the trajectory based wavepacket propagation …