Collision dynamics of three interacting atoms: The Faddeev equations in a diabatic electronic basis

Abstract

Starting with all the electrons and nuclei making up a system of three atoms, we introduce a basis of antisymmetrized products of atomic states to define a matrix Hamiltonian partition applicable to atom–diatom collisions. We derive a three-atom generalization of the Faddeev equations in terms of diatomic transition operators. Equations are obtained for three-atom rearrangement transition operators that are then reduced to sets of effective two-body (atom–diatom) equations by introducing separable expansions of the diatomic transition operators. We also discuss the permutational symmetry of identical nuclei and briefly describe how the formalism applies to the H3 and FH2 systems.