Indirect dissociative recombination of water molecule at low electronic energies

We present a theoretical study of the indirect dissociative (DR) recombination of the water molecular ion H$_{2}$O$^{+}$ at low collisional energies. The approach is based on the computation of the scattering matrix just above the ionization threshold and enables the explicit determination of all diabatic electronic couplings responsible for dissociative recombination. We use the multi-channel quantum- defect theory to demonstrate the precision of the scattering matrix by reproducing accurately ab initio Rydberg state energies of the neutral molecule. We also present our latest results on H$_{2}$O$^{+}$ with our previous results on the DR of linear molecular ions N$_{2}$H$^{+}$ and HCO$^{+}$ and demonstrate the crucial role of the previously overlooked longitudinal modes for linear polyatomic ions with large permanent dipole moment.