Near Edge X-Ray-Absorption Fine-Structure Determination of Alkyl-Chain Orientation: Breakdown of the "Building-Block" Scheme

ln the Letter we reported NEXAFS (near edge x-ray-absorption fine-structure) measurements for different thin films containing long alkyl chains, the analysis of which indicated that the so-called "building-block" scheme commonly used to interpret NEXAFS data for larger molecules fails to describe the angular dependence of the C-C resonance at 293.4 eV. We also presented results of ab initio SCF-RHF calculations which supported our experimental conclusions. In the meanwhile, however, we discovered an error in the plotting procedure for the transition dipole moments (TDM) as ob- tained from the ab initio calculations. When correctly evaluated the calculations indicate the presence of two reso- nances with significant TDM's at the energy where experimentally the C-C resonance is observed. This behavior is not predicted by the building-block scheme and has not been observed experimentally, as the C-C resonance half-width