A NEW COMPUTATIONAL ALGORITHM FOR GREENS-FUNCTIONS - FOURIER-TRANSFORM OF THE NEWTON POLYNOMIAL EXPANSION

A new iterative method to compute the Green's function for continuum systems is presented. It is based on a Newton polynomial expansion of the corresponding propagator, followed by accurate half-Fourier transformation. The new technique is remarkably stable, accurate and can handle very large systems. We apply the new method to the calculation of three-dimensional quantum reaction probabilities for the initial state-selected D + H-2(n,j) --> DH + H reaction. We find excellent agreement with previous results, requiring very modest amounts of CPU time.