Collision dynamics of three interacting atoms: Permutational symmetry for identical nuclei

Abstract

Expressions have been obtained for scattering probability amplitudes of direct, atom‐exchange, and dissociative processes in atom‐diatom collisions involving two or three identical nuclei. This is done in terms of free states written as products of electronic, nuclear coordinate, and nuclear spin wavefunctions. Symmetrized amplitudes are re‐expressed in terms of unsymmetrized ones and nuclear spin weights are factored out. The Faddeev equations for identical nuclei interacting through sums of pairs of spin‐dependent potentials are uncoupled and used to expand amplitudes in powers of pair transition operators. It is found that a spectator‐type mechanism contributes to the direct processes in the single collision approximation. The corresponding probability amplitudes are explicitly written down.