Channel Mixing Effects in the Dissociative Recombination ofH3+with Slow Electrons

We discuss the low-energy dissociative recombination of ${\mathrm{H}}_3^{+}$, which strongly influences the abundance of this ion in diffuse interstellar molecular clouds. The kinetic couplings between the ionization continuum and the dissociative ground state of ${\mathrm{H}}_3$ have been used as input to a two-dimensional wave packet calculation of dissociation dynamics. The cross section obtained for direct dissociative recombination is much smaller than the latest experimental results. However, a multichannel quantum defect treatment shows that an indirect mechanism via bound Rydberg states of ${\mathrm{H}}_3$ prevails for this process.