Allred-Rochow and Gordy Scales

The Allred-Rochow scale is, after the one of Pauling, the most commonly used among the experimental studies and is based on the following principle (Allred Rochow, 1958 Allred, 1961)  

PRINCIPLE ENll (of Allred-Rochow) The electronegativity of an atom is given by the attraction force between the shielded nucleus and the electron found at a distance equal with the covalent radius and is expressed as follows  

This principle states the introduction of the force concept in explaining the chemical bonds and in defining the electronegativity. In the last relation the effective charge of the shielded nucleus, Z = = Z-s,h calculated 

A modification of Allred-Rochow relation in the way proposed by Huheey Z Z - hS, with S the partial atomic charge of the atom in molecule, is insignificant in terms of concept. 

Boyd and Markus, in 1981, took the concept of force in defining the atomic electronegativity and by nonempirical calculations reached the expression  

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