Momentum imaging measurements from two experiments are presented and interpreted with the aid of ab initio theoretical calculations to describe the dissociative electron attachment (DEA) dynamics of CO${}_2$. The dynamics of the transient negative ions of CO${}_2^{-}$ involve several conical intersections taking part in mechanisms that have only recently been understood. We address the problem of how the 4-eV ${}^2{\Pi }_u$ shape resonance in CO${}_2$ proceeds to dissociate to CO(${}^1{\Sigma }^{+}$) $+$ O${}^{-}$(${}^{2}P$) by DEA.

• Received 21 May 2013

DOI:https://doi.org/10.1103/PhysRevA.88.032703