Journal article
Deexcitation dynamics of Rydberg states in O₂: II. Vibrational and rotational structure of 2σ⁻¹_{u}(c⁴Σ⁻_{u})(ns/nd)σ_{g}³Σ⁻_{u} (v = 0, 1) states
Publication Details
Authors:  Ehresmann, A.; Werner, L.; Klumpp, S.; Schmoranzer, H.; Demekhin, P.; Lagutin, B.; Sukhorukov, V.; Mickat, S.; Kammer, S.; Zimmermann, B.; Schartner, K.

Journal:  Journal of Physics B: Atomic, Molecular and Optical Physics 
Abstract
The competition between autoionization and neutral dissociation (ND) of the vibronic Rydberg states 2σ^{1}_{u}(c^{4}Σ^{}_{u})(ns/nd)σ_{g}^{ 3}Σ^{}_{u}(v = 0, 1) has been investigated using an experiment of photoninduced fluorescence spectroscopy (PIFS) and the simultaneous measurement of the photo ion yield. The experiments were performed with monochromatized synchrotron radiation from BESSY II with a very narrow bandwidth of ΔE = 1.5 meV at 23 eV where it was possible to observe single rotational branches. The experiments are compared to ab initio calculations for the partial autoionization and dissociation widths and to the corresponding simulations of the spectroscopic shape of the rovibronic branches. For more precise calculations of the dissociation widths, diabatic potential curves of the 2σ^{1}_{u}(c^{4}Σ^{}_{u}) states of the O_{2}^{+} are extracted from the adiabatic ones and improved calculations for molecular orbitals of the Rydberg and Auger electrons are used.