THE CALCULATION OF PRODUCT QUANTUM STATE DISTRIBUTIONS AND PARTIAL CROSS-SECTIONS IN TIME-DEPENDENT MOLECULAR COLLISION AND PHOTODISSOCIATION THEORY

A new method of analyzing the results of multidimensional time-dependent quantum dynamical wavepacket calculations in terms of the product quantum state distributions is presented. The method requires knowledge only of the time-dependent projection coefficients of the wavepacket onto individual product quantum states along a cut in the exit valley of the photodissociation or reaction process. The squares of the Fourier transforms of these coefficients then directly yield the cross-sections of interest. The great advantage of time-dependent quantum dynamics, namely that a single wavepacket calculation yields the cross-sections at all energies of interest, is fully exploited.