Theory of semiclassical transition probabilities for inelastic and reactive collisions. IV. Classically-inaccessible transitions calculated by integration along complex-valued trajectories

Abstract

We calculate semiclassical S-matrix elements Smn by numerical integration along complex-valued trajectories, by avoiding (simply) previously reported trajectory divergences. Now, one can numerically calculate even {divides}Smn{divides} ≈ 10-11 for the Secrest-Johnson system (their lowest {divides}Smn{divides}2), instead of only {divides}Smn{divides}2 > 10-3. Agreement is excellent. © 1972.