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Abstract: The O 1s photoelectron satellite spectrum of water has been recorded with high resolution and some vibrational structures were detected. The electronic and vibrational structures observed in the experimental spectrum are well interpreted with the aid of the molecular ab initio calculations based on the symmetry adapted cluster-configuration interaction (SAC-CI) method. [Copyright &y& Elsevier]

The N 1s→π* photoabsorption profile of N2 is quantitatively analysed. New spectroscopical constants for the N 1s−1π* core-excited state are determined from NEXAFS spectra and compared to previously published data. The accuracy of the new spectroscopical constants is discussed and error bars are given for the present data analysis. The goodness of the new spectroscopical constants is demonstrated by lifetime vibrational interference (LVI) simulations of the resonant Auger decay from the N 1s−1π* core-excited state to the A2Πu singly ionized final state of N2. These new values give a much better agreement with recently obtained experimental data compared to the previously published ones. [Copyright &y& Elsevier]

We show that the undular stray light, diffusely scattered by the optical system of a synchrotron beamline, can play an important role in the formation of high-resolution resonant photoelectron (RPE) spectra. The influence of the stray light is mediated through the Stokes doubling effect, with the Lorentzian tail of the spectral function being replaced by a more complicated form. This effect is shown to appear in the high-resolution resonant photoelectron spectrum of the N2 molecule in which the spectral shape of the “non-Raman (NR) bands” differs qualitatively for the A2Πu and X2Σ+g final states. A particularly large enhancement of the non-Raman Stokes line is observed for the A-state while the picture is inverted for the X-state where the non-Raman band is suppressed. It is shown that the resonant photoemission profile is affected by two qualitatively different detunings, the detuning of the monochromatized line relative to the photoabsorption line and the detuning of the undulator harmonic relative to the same reference line. The experimental data show that the relative intensity of the non-Raman line strongly depends on the tuning of the undulator harmonic with respect to the selected monochromator bandpass, leading to a strong decrease of the Stokes line intensity for certain undulator detunings. A clear red-shift asymmetry for the decrease in the Stokes line intensity is observed when the monochromator line is detuned towards negative photon frequencies, whereas the picture is reverted for the situation of a positively detuned monochromator line. The results show the necessity to control the stray light and to investigate both the Raman and non-Raman contributions to the spectral profiles in order to avoid misinterpretation and in order to make full use of the information available in resonant photoemission spectra of molecules. [Copyright &y& Elsevier]

High-resolution electron spectroscopy applied under resonant Auger-Raman conditions is shown to be a powerful tool for characterizing complex potential energy surfaces of core-excited states in polyatomic systems. BF3 is used as a prototype molecule: excitation of the B1s →2a2″ transition leads to an exceptional out-of-plane vibrational excitation resolved over a wide energy range (3.6 eV). The photon energy dependence of the spectra through the resonance profile is rationalized in the frame of the relative slopes of the potential energy curves along the boron out-of-plane displacement coordinate. [Copyright &y& Elsevier]