Average Valence Electron Energies

Of particular interest to chemists is a quantitative measure of how tightly an atom holds its valence electrons. We define the Average Valence Electron Energy (AVEE) as... 

Table 2. Average valence electron energies for several elements [MJ/mole).

Other treatments " have led to scales that are based on different principles, for example, the average of the ionization potential and the electron affinity, " the average one-electron energy of valence shell electrons in ground-state free atoms, or the compactness of an atom s electron cloud.In some of these treatments electronegativities can be calculated for different valence states, for different hybridizations (e.g., sp carbon atoms are more electronegative than sp, which are still more electronegative than and even differently for primary, secondary,... 

Allen, L. C. (1989). Electronegativity is the average one-electron energy of the valence-shell electrons in ground-state atoms. J. Amer. Chem. Soc. Ill, 9003-14. 

More recently Men33 has proposed that electronegativity be defined in terms of the average one-electron energy of valence shell electrons in ground-state free atoms which may be obtained spectroscopically. This quantity is termed the configuration energy ... 

Table 10.2 Comparison of average d-valence electron energies (Sj), d-valence electron band width (W), and adsorption energies of C (E ).

A comparison of the changes in PDOS for C adsorbed to the Ru(OOOl) surface and C adsorbed atop of the Ru (1120) surface will indicate the relative importance of average d-valence electron energy diHerences versus d-bandwidth changes. In Figure 10.5, changes in d-valence band PDOS are shown for the C atom adsorbed atop a Ru atom of the Ru(1120) surface. 

Treating the average of the total (valence) electronic energy with respect with the total number of the electrons in accordance with Thomas-Fermi theory so better closing with the parabolic E-to-N dependency prescribed for atoms and molecules, as compared with the previous point ... 

FIG U RE 3.4 Spectroscopic electronegativities for groups I-VIII of representative elements. (Adapted from L.C. Allen, Electronegativity Is the Average One-Electron Energy of the Valence-Shell Electrons in Ground-State Free Atoms. J. Am. Chem. Soc. Ill, no. 25 (1989) 9003-9014.)... 

Saunders states. Assuming that the valence electrons at the top of the band have the average hybrid character 3d34s4p2, the interaction energy of one of these valence electrons and an atomic electron, assumed to be approximately a 3d electron, is found to be —2707 cm-, or —0.334 ev, with probable error about 10%. 

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