Seminars Archive

Vibrationally resolved core-level spectroscopy at molecules in the gas-phase

Abstract
During recent years a substantial improvement of the spectral resolution and flux of synchrotron radiation sources in the soft X-ray region has been achieved. This improvement allows to resolve the vibrational fine-structure in core-level processes of molecules and provide detailed information about the potential energy surfaces - like equilibrium distance and vibrational energies - of the states involved. High resolution photoabsorption spectra of SiX4 molecules below the Si-2p ionization threshold are presented and the basic ideas of vibrational analysis are discussed. For silane (SiH4/SiD4) a model for the presence of different vibrational modes in the spectrum is presented. For SiH4 and SiD4 an isotope shift of the Si-2p ionization thresholds and for SiCl4 the influence of hot bands is reported. The ideas of vibrational analysis are applied for the first time in full detail to the Br 3d-1 -> 4pp-2 normal Auger spectra of HBr. From the analysis reliable information about the potential energy surfaces of the 4pp-2 final states are derived and compared with most recent HF-calculation on the CI-level.