Site-specific formation of metastable dications following inner-shell ionization of CO2

An Auger-electron–ion coincidence method is applied to study the site-specific formation of metastable CO 2 2+ in the C1s and O1s Auger decays of CO 2 . It is found that only dication states with the electronic configuration of 1π g −2 are relevant to the metastable formation. These dication states are favorably produced in the O1s Auger decay, because of the charge distribution of the 1π g orbital localizing at the O site. Fragmentation channels of dissociative CO 2 2+ states are also investigated.