Detailed dynamics of direct three-body recombination of singly charged ions

Abstract

We consider the main aspects of detailed dynamics of the reactions of direct three-body ion–ion recombination Cs⁺ + X⁻ + R → CsX + R (X⁻ = F⁻, I⁻ and R = Ar, Xe) for non-central encounters of the ions. The reactions are simulated by the quasiclassical trajectory method using diabatic semiempirical potential energy surfaces proposed previously. The recombination mechanisms are studied via visualization of randomly selected trajectories for each of the four systems. Comparison of trajectories for different systems with identical sets of initial conditions is carried out. For most of the presented trajectories, the ion encounter energy and the third body energy are equal to 1 eV. The characteristic function of recombination is defined, this function depends on 13 arguments including eight kinematic parameters. It is shown that the transfer of excess energy from the ion pair to the neutral atom can occur, in particular, via an encounter of the R atom with the Cs⁺ ion, via an encounter of the R atom with the X⁻ ion, or via successive encounters of the R atom with both the ions, as well as via an “insertion” of the R atom between the ions.