Core-electron binding energies CEBEs

In an effort to better understand the differences observed upon substitution in carvone possible changes in valence electron density produced by inductive effects, and so on, were investigated [38, 52]. A particularly pertinent way to probe for this in the case of core ionizations is by examining shifts in the core electron-binding energies (CEBEs). These respond directly to increase or decrease in valence electron density at the relevant site. The CEBEs were therefore calculated for the C=0 C 1 orbital, and also the asymmetric carbon atom, using Chong s AEa s method [75-77] with a relativistic correction [78]. 

Costa, M.C.A. and Takahata, Y. (2003) Core electron binding energy (CEBE) shifts as descriptors in structure-activity relationship (SAR) analysis of neolignans tested against Loishmania donovcmi. 

Core-electron ionization spectra contain the information not only about inner-core electrons but also about valence electrons and chemical bonds. Extensive experimental studies have measured the core-electron binding energies (CEBE) of numerous molecules [112,113] and the recent development of X-ray photoelectron spectroscopy (XPS) has enabled the detailed analysis of the satellites accompanied by the inner-shell ionization. 

Table 1 Core-Electron Binding Energies (CEBEs, in eV) for the trihydroxy-form of y-APS, y-APS(OH)s, compared with a tentative three-peak decomposition of the Cls region of spin-coated y-APS. All values are referenced to the Fermi level of the spectrometer [22]...

The core ionization potentials, more frequently called core electron binding energies (CEBEs) when molecular systems are studied, have been also recently calculated for the tautomeric structures of thio- and seleno-cytosine [35]. The role of relativistic effects in ly ionization have been studied for selenocytosine by the comparison of the nonrelativistic and relativistic SCE and MP2 results of the calculations. 

Shim et al. used the MCPs in the calibration of the AMP2 method for calculating core electron binding energies (CEBE) [263]. In that method, MCPs are used for aU atoms except for the one from which the Is electron is removed (that atom is treated... 

The performance of DFT in the optimization of molecular geometry is summarized in Section 4. In Section 5, we present DFT results for the vibrational spectra of molecules. It is well known that HF harmonic vibrational frequencies are about 10% higher than the experimental harmonic frequencies. Vibrational frequencies computed at correlated levels of methods improve the agreement, but they are usually computationally too costly to be feasible for medium-sized molecules. Since DFT is computationally more economical than the HF method, the accuracy of DFT predicted vibrational frequencies is of great interest to us. Section 6 summarizes the DFT results for electron spectroscopy including core-electron binding energies (CEBEs) which are measured by the so-called electron spectroscopy for chemical analysis (ESCA), and inner-shell electron excitation spectra (ISEES). 

---