Classical S matrix: Application of the Bessel uniform approximation to a chemical reaction

The Bessel uniform approximation developed by Stine and Marcus is applied to the collinear H + H₂ reaction on Diestler's potential energy surface no. 3 to which we have previously applied other orders of approximation of classical S matrix theory. It appears that an accurate treatment of this system by classical S matrix theory requires interference of real and complex trajectories. Calculations were also performed on two other potential energy surfaces in order to more clearly understand the interrelationships of previous semiclassical and quasiclassical studies of this reaction.