RESUMEN
The C 1s X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy of two buckyonion fullerene C20@C60 isomers were theoretically simulated by density functional theory (DFT) method. In this paper, we mainly investigated the relationship between spectroscopy and structure and obtained the spectral dependence on the structures with different symmetries. Our results showed that both XPS and NEXAFS spectra exhibited remarkable dependence on the molecular structures, thus these two spectroscopic techniques could be adopted to identify the two C20@C60 isomers effectively. Additionally, we found that the building block approach could not predict the spectra for C20@C60 isomers due to the strong interaction between the two layer cages. Finally, we studied the decompositions of the total spectra from carbon atoms in different local environments to analyse the origins of the main features.
RESUMEN
In this paper, the six C32 isomers which were of crucial importance in the manufacture of new electronic components were identified by X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS). For the discernment, geometry optimizations of the six isomers have been carried out, and the C1s XPS and NEXAFS spectra have been simulated in the frame of density functional theory (DFT). XPS spectra, as accurately reflection of different chemical environments where a particular element was located, provided an effective way to identify the six isomers of C32. The NEXAFS spectra, which were commonly used in the electronic structure detection, captured information of unoccupied orbital and showed many recognizable characteristics. To further investigate the source of spectral features, the spectral components calculated from different types of carbon atoms in each C32 isomer also have been well explored and discussed.