Peak, asymmetrical definition

How then, can one recover some quantity that scales with the local charge on the metal atoms if their valence electrons are inherently delocalized Beyond the asymmetric lineshape of the metal 2p3/2 peak, there is also a distinct satellite structure seen in the spectra for CoP and elemental Co. From reflection electron energy loss spectroscopy (REELS), we have determined that this satellite structure originates from plasmon loss events (instead of a two-core-hole final state effect as previously thought [67,68]) in which exiting photoelectrons lose some of their energy to valence electrons of atoms near the surface of the solid [58]. The intensity of these satellite peaks (relative to the main peak) is weaker in CoP than in elemental Co. This implies that the Co atoms have fewer valence electrons in CoP than in elemental Co, that is, they are definitely cationic, notwithstanding the lack of a BE shift. For the other compounds in the MP (M = Cr, Mn, Fe) series, the satellite structure is probably too weak to be observed, but solid solutions Coi -xMxl> and CoAs i yPv do show this feature (vide infra) [60,61]. 

Figure 4.13 For asymmetrical reflections the peak position depends on its definition.

Al NMR. The Al NMR (Table I) is simple to interpret as it has only one peak at 69.2 ppm which indicates a tetracoordinate A1 center, as expected for the proposed precursor structure 14-16). There is a definite change in Al NMR signals on going from alumatrane to the precursor (Figure 2). Alumatrane has two very broad peaks, centered at 61.5 and 5.4 ppm, indicating tetracoordinate and hexacoordinate A1 centers respectively, as expected for an asymmetric dimer in solution. The KAS precursor has only one narrow peak at 69.2 ppm, indicating a more symmetric, tetracoordinate A1 center. 

---