Lawrence Berkeley National Laboratory

The potential energy surfaces corresponding to the long-lived fixed-nuclei electron scatering resonances of H$_2$O relevant to the dissociative electron attachment process are examined using a combination of ab initio scattering and bound-state calculations. These surfaces have a rich topology, characterized by three main features: a conical intersection between the $^2A_1$ and $^2B_2$ Feshbach resonance states; charge-transfer behavior in the OH ($^2\Pi$) + H$^-$ asymptote of the $^2B_1$ and $^2A_1$ resonances; and an inherent double-valuedness of the surface for the $^2B_2$ state the C$_2v$ geometry, arising from a branch-point degeneracy with a $^2B_2$ shape resonance. In total, eight individual seams of degeneracy among these resonances are located.