Yonghe Zhang ioniccovalent theory applications (34)
American Huilin Institute http://www.amhuilin.com/
Cherkasov et al. in “Russian Chemical Reviews” proposed a review titled “The concept of electronegativity. The current state of the proboem”. They concluded: “Electronegativity is the ability of an element to attract electrons on formation of chemical bonds, which depends on its nature and valence state”. And they pointed out that the current state of the problem is that the electronegativity is not an interpretation of the definite and unambiguous valence state. Pauling’s definition which is essentially correct, therefore requires refinement in each specific instance.
Allred-Rochow method  for the description of electronegativity as a “force” corresponds best to its initial definition by Pauling  and is one of the best known and most frequently employed. Nevertheless, the force acting on an electron is estimated arbitrarily by the Slate rule, which not depends on its nature of bond formation and the unambiguous valence state.
On Zhang electronegatiavity system [4,5], Cherkasov et al. reviewed: “ the force acting on an electron (and hence electronegativity) can be determined within the framework of the inverse quadratic dependence on the radius rc using the ionization potential of the valence electron Iz and the effective principal quantum number n*:
Xz = 0.241 n*( Iz /R) ½rc-2 + 0.775 ”
According to the conclusion by Cherkasov et al., Zhang electronegativity not only developed the “force” approach to the determination of electronegatiavity but also solved the current problem of the ambiguous valence state. Therefore, Zhang electronegativity is best which depends on the nature of bond force and valence state.
 A. R. Cherkasov, V. I. Galkin, E. M. Zueva, R. A. Cherkasov, Russian Chemical Reviews, 67, 5 (1998) 375-392.
 A. L. Allred and E. G. Rochow, J. Inorg. Nucl. Chem. 5 (1958) 264-268.
 L. Pauling, J. Am. Chem. Soc. 54 (1932) 3570.
 Y. Zhang, J. Molecular Science, (Chinese) 1 (1981) 125.
 Y. Zhang, Inorg Chem. 21 (1982) 3886.