The fragmentation of the doubly-charged carbon dioxide molecule is studied
after photoexcitation to the C 1s 12π u and O 1s 12π u states using a
multicoincidence ion-imaging technique. The bent component of the Renner-
Teller split states populated in the 1s→ π* resonant excitation at both the
carbon and oxygen 1sionization edges opens pathways to potential surfaces in
highly bent geometries in the dication. Evidence for a complete deformation of
the molecule is found in the coincident detection of C+ and O+2 ions. The
distinct alignment of this fragmentation channel indicates rapid deformation
and subsequent fragmentation. Investigation of the complete atomization
dynamics in the dication leading to asymmetric charge separation shows that
the primary dissociation mechanisms, sequential, concerted, and asynchronous
concerted, are correlated to specific fragment kinetic energies. The study
shows that the bond angle in fragmentation can extend below 20°