Recoil opacity function and angular momentum transfer across a deep well for heavy heavy-light chemical reactions

The shape of the exit impact parameter function, P(bʹ), for the Mg+FH reacting system - taken as a prototype for alkaline earth+hydrogen halide reactions - is found to be a quite sensitive indicator of the reaction pathway. In particular, we have found that there exists a mass-(isotopic) and energy-independent cut-off bʹ* value of the product impact parameter b′ definitely separating the direct and complex contributions to P(bʹ). The value of bʹ* was found to be associated with the equilibrium intemuclear distance of H-Mg in the HMgF intermediate complex.