Monte Carlo simulation of RRKM unimolecular decomposition in molecular beam experiments. II. Application to angular distributions and absolute cross sections for the system K+RbCl

Abstract

The Monte Carlo simulation algorithm, which we have developed recently, is now applied to one of the well studied alkali—alkali halide systems. The calculations show, that quite good agreement between experiment and theory is found with semiclassical energy distributions and ordinary RRKM theory. This applies also to the branching ratio, which is now found to be around 0.67 instead of the previously reported theoretical value of 1.0–1.3. The good agreement here is due to the exact treatment of angular momentum conservation, the correct evaluation including all initial distributions and the elimination of previous inaccuracies, like the SWHT formulas. By inclusion of three nonstatistical effects, based on trajectory calculations and dynamical arguments, excellent agreement between theory and the absolute experiments is found. One conclusion is, that the usual large orbital angular momentum approximation is not good even in this case with large cross sections.