Direct Three-Body Recombination of Halogen Atoms

Since the emergence of chemical physics in the 20^th century, the three-body process known as atom recombination has been a subject of interest. The earliest experimental investigations of atom recombination took place in the 1930s, which involved the recombination of halogen atoms (X) in inert gases (M). For the next several decades, researchers sought to characterize the reaction X + X + M → X₂ + M on both the experimental and theoretical front, finally concluding that this termolecular event is the result of a two-step, indirect bimolecular process known as the Lindemann-Hinshelwood mechanism. In this poster, we investigate the recombination of halogens under a one-step, direct termolecular process using classical trajectories in hyperspherical coordinates, where we find that the often-neglected direct recombination mechanism is critical in describing these reactions.