Two-vector correlations and microscopic branching in chemical dynamics : alignment and orientation effects for the Mg + HF → MgF + H reaction

Correlations between vector parameters characterizing the Mg+HF→MgF+H reaction have been investigated by carrying out extended trajectory calculations. For this study, use has been made not only of the traditional trajectory output, but also of vector distributions and related Legendre moments. Particular attention has been paid to the correlation of the direction of the final rotational angular momentum to that of the reagents’ relative velocity. For reactive events, the final rotational angular momentum was found to be perpendicularly polarized. The degree of alignment is high for trajectories taking a direct path from the saddle to the product asymptote, while the alignment is partially disrupted for those sampling the intermediate HMgF well. These results are compared with predictions from the constrained product orbital angular momentum (CPOAM) model.