Dissociative electron attachment to theH2Omolecule I. Complex-valued potential-energy surfaces for theB12,A12, andB22metastable states of the water anion

Abstract

We present the results of calculations defining global, three-dimensional representations of the complex-valued potential-energy surfaces of the $^{2}B_{1}$, $^{2}A_{1}$, and $^{2}B_{2}$ metastable states of the water anion that underlie the physical process of dissociative electron attachment to water. The real part of the resonance energies is obtained from configuration-interaction calculations performed in a restricted Hilbert space, while the imaginary part of the energies (the widths) is derived from complex Kohn scattering calculations. A diabatization is performed on the $^{2}A_{1}$ and $^{2}B_{2}$ surfaces, due to the presence of a conical intersection between them. We discuss the implications that the shapes of the constructed potential-energy surfaces will have on the nuclear dynamics of dissociative electron attachment to ${\mathrm{H}}_{2}\mathrm{O}$.