Correlation effects in the valence x-ray photoionization spectra of ethylene,butadiene, and hexatriene

The x-ray photoemission spectra of the ethylene, butadiene, and hexatriene compounds were investigated using one-particle Green's function calculations which are exact up to third order in correlation. This study points to the importance of initial-state correlation and cross-section effects for a consistent reproduction of satellite bands recorded under x-ray photoionization. By extrapolating the results obtained to larger unsaturated hydrocarbons, it is clear that the signal recorded in the inner-valence region of polyacetylene must be exclusively assigned to many-body structures. This study also provides evidence for a partial contamination of the outer-valence band by shake-up lines. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 63: 465–481, 1997