Statistical dynamics of bimolecular recombination of alkali and halide ions

By means of quasiclassical trajectory simulation on semiempirical diabatic potential energy surfaces proposed earlier, we have studied the dynamics of the bimolecular recombination reactions RCs + + X – → CsX + R for X – = F – , I – and R = Ar, Xe. The results obtained include the excitation functions of the reactions in the range of collision energies E col from 0.1 to 2.5 eV as well as the distributions of the energy of the flying apart of the products, the opacity functions, and the distributions of the vibrational and rotational energies of the CsX molecule at E col = 0.1 , 0.2, and 0.3 eV. For each of the four systems considered, the cross section of bimolecular recombination drops as the collision energy grows. In all the cases, the distributions of the vibrational energy of the product molecule are strongly non-equilibrium, whereas the distributions of the rotational energy are relatively close to equilibrium ones. On the whole, the behavior of the statistical dynamical characteristics of bimolecular recombination turns out to depend on the halide ion X – to a much greater extent than on the neutral atom R. Graphical abstract