Hidden Resources of Coordinated XPS and DFT Studies

Electronic configuration of chemically bound atoms, at the surface or in the bulk of a solid, contains the traps for energy absorption provided by the valence band electron transitions; the core-level excitation of any origin is coupled with traps forming the mul- tichannel route for energy dissipation. This chapter displays tracing over these channels by means of X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT). Conformity between energy losses in the XPS spectra and electron transitions in relevant unit cells is verified by the examples of the pristine and half fluorinated graphite C 2 F, and the Br 2 -embedded C 2 F. Perfect XPS-DFT combination can be useful for material science providing exhaustive data on state and geometry of the atoms in a sample, regardless the field of its application. The valence band is insensitive to the energy source for its excitation. It makes the behavior of energy losses in XPS spectra of the atoms to be a descriptor of bonding between these atoms in multicomponent materials. Moreover, the state of any component can be tracked through change or invariability of satellites in the relevant XPS spectra, obtained in the course of the external influence, thus revealing a wear performance of the material.