Adiabatic channel study of the capture of nitrogen and oxygen molecules by an ion: Effect of nuclear symmetry and spin-spin interaction

Within the adiabatic channel treatment of ion-molecule capture we have calculated the low temperature capture rate constants of N-2((1) Sigma(g)(+)) and O-2((3) Sigma(-)) in collisions with positive and negative ions. In both cases, the charge-quadrupole and the anisotropic charge-induced dipole interactions produce noticeable deviations from the Langevin rate constant. The rate constants calculated with account for the anisotropic interaction, in addition, are substantially affected by nuclear symmetry; in the case of O-2((3) Sigma(g)(-)), the fine-structure spin-spin interaction strongly manifests itself in the rate constants.