Molecular dynamics of dissociative electron attachment in water
Abstract
Classical trajectory calculations have been used to model dissociative electron attachment (DEA) processes in water. In previously reported experiments, DEA cross-sections show maxima at three different energies between ca. 6 and 12 eV; these have been ascribed to the formation and dissociative decay of three different resonant (anion) states of symmetry 2B1, 2A1 and 2B2 whose parent states are the Ã1 B1, B 1A1 and C 1B2 states, respectively, of neutral water. The present model calculations show that the essential features of the experimental findings can be reproduced using only two anionic potential surfaces; furthermore, most of the observed product ions follow from initial excitation to one (the lower-lying in symmetric geometries) of these. If the two surfaces are related to resonances of symmetry 2B1 and 2B2, then all of the observed features associated with resonant electron scattering from water can be rationalised.