Quantum chaos in atom–diatom reactive collisions

An analysis of the distribution of the squared S-matrix elements and of the nearest neighbour distribution of the eigenphases of the S-matrix has been performed for the two reactive atom–diatom collisions N(2D)+H2→NH+H and F(2P)+D2→FD+D at fixed total energy. The first is an indirect reaction which involves a long-lived intermediate complex, whereas the second is a direct reaction with a short-lived intermediate complex. Quantum chaos has been found for the N+H2 reaction whereas the F+D2 reaction follows a non-chaotic regime.