  We report the results of a first-principles study of dissociative electron
attachment to H2O. The cross sections are obtained from nuclear dynamics
calculations carried out in full dimensionality within the local complex
potential model by using the multi-configuration time-dependent Hartree method.
The calculations employ our previously obtained global, complex-valued,
potential-energy surfaces for the three (doublet B1, doublet A1, and doublet
B2) electronic Feshbach resonances involved in this process. These three
metastable states of H2O- undergo several degeneracies, and we incorporate both
the Renner-Teller coupling between the B1 and A1 states as well as the conical
intersection between the A1 and B2 states into our treatment. The nuclear
dynamics are inherently multidimensional and involve branching between
different final product arrangements as well as extensive excitation of the
diatomic fragment. Our results successfully mirror the qualitative features of
the major fragment channels observed, but are less successful in reproducing
the available results for some of the minor channels. We comment on the
applicability of the local complex potential model to such a complicated
resonant system.
