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Normal Auger electron spectra from Kr2p hole states, L 23 M 45 M 45 and L 23 M 23 M 45, have been measured using monochromatized synchrotron radiation and a high resolution electron spectrometer. Measured spectra were reproduced with a fitting calculation, where Voigt functions including an instrumental resolution and natural lifetime widths of related core hole states were used. At most final states estimated energies for spectral peaks agree with those by electron and ion beam techniques. Relative intensities for some peaks are appreciably different from the previous results.

Auger electron spectra were studied by scanning the photon energy near the L 3 threshold of krypton. Two resonant transitions were observed in the photon energy region 1673–1678 eV for the first time. They were identified to be the resonant 3d -2 5s and 3d -2 4d states originating in the 2p 3/2-1 5s and 2p 3/2-1 4d excitations, respectively.

Resonant Auger electron spectra following Kr:2p → 5s photoexcitation have been measured for the first time using monochromatized undulator radiation and a cylindrical mirror electron energy analyser. It is found that the kinetic energy of the resonant Auger electron is higher than that of the corresponding normal Auger electron. The angular distribution of the resonant Auger electrons is nearly isotropic relative to the polarization direction of the incident light.

Angle-resolved energetic-ion-yield spectra were observed in the region of the O $1s$ to Rydberg excitation of ${\mathrm{CO}}_{2}$ with incident photon energy resolving power $E/\ensuremath{\Delta}E\ensuremath{\simeq}14000.$ The assignments of the electronic states were established in accordance with the angular distribution data. All the observed vibrational structures were assigned to the antisymmetric stretching vibrations caused by the vibronic coupling between the nearly degenerate O $1s$ core-excited states. A Franck-Condon analysis was performed within the linear coupling model.

The vibrational structure of the $\mathrm{O} {1s}^{\ensuremath{-}1}{2b}_{2}$ core-excited state of ${\mathrm{H}}_{2}\mathrm{O}$ is observed and ascribed to the mixture of symmetric stretching and bending motions with ${a}_{1}$ symmetry. The formation of ${\mathrm{H}}_{2}^{+}$ is found to increase linearly with an increase in energy stored in the nuclear motion of the $\mathrm{O} {1s}^{\ensuremath{-}1}{2b}_{2}$ state, demonstrating that this dissociation channel is mediated by the nuclear motion in the core-excited state. The reaction pathway to the ${\mathrm{H}}_{2}^{+}$ formation along the Auger final state of ${\mathrm{H}}_{2}{\mathrm{O}}^{+},$ mediated by the nuclear motion before the Auger decay, is discussed with the help of ab initio potential surfaces of the Auger final states.