Momentum imaging measurements from two experiments are presented and interpreted with the aid of new ab initio theoretical calculations to describe the dissociative electron attachment (DEA) dynamics of CO2. 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 Πu shape resonance in CO2 proceeds to dissociate to CO( 1 Σ + ) + O − ( 2 P) by DEA.

In this work we present a comprehensive and detailed study of Interatomic Coulombic Decay (ICD) occurring after irradiating argon dimers with XUV-synchrotron radiation. A manifold of different decay channels is observed and the corresponding initial and final states are assigned.Additionally, the effect of nuclear dynamics on the ICD electron spectrum is examined for one specific decay channel. The internuclear distance-dependent width Γ(R) of the decay is obtained from the measured energy distribution employing a classical nuclear dynamics model.

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A dramatic symmetry breaking in K-shell photoionization of the CF 4 molecule in which a core-hole vacancy is created in one of four equivalent fluorine atoms is displayed in the molecular frame angular distribution of the photoelectrons. Observing the photoejected electron in coincidence with an F + atomic ion after Auger decay is shown to select the dissociation path where the core hole was localized almost exclusively on that atom. A combination of measurements and ab initio calculations of the photoelectron angular distribution in the frame of the recoiling CF 3 + and F + atoms elucidates the underlying physics that derives from the Ne-like valence structure of the F(1s −1 ) core-excited atom.

An ion-momentum spectrometer is used to study the dissociative dynamics of electron attachment to molecules. A skimmed, supersonic gas jet is crossed with a pulsed beam of low-energy electrons, and the resulting negative ions are extracted toward a time- and position-sensitive detector. Calculations of the momentum in three dimensions may be used to determine the angular dependence of dissociative attachment as well as the energetics of the reaction.