Definition of Electronegativity

Electronegativity can be roughly defined as the tendency of an element to gain electrons and form negative ions. In the partial Periodic 

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A very simple definition of electronegativity also finds a foundation in DFT. The definition is... 

Besides the already mentioned Fukui function, there are a couple of other commonly used concepts which can be connected with Density Functional Theory (Chapter 6). The electronic chemical potential p is given as the first derivative of the energy with respect to the number of electrons, which in a finite difference version is given as half the sum of the ionization potential and the electron affinity. Except for a difference in sign, this is exactly the Mulliken definition of electronegativity. ... 

Heats of formation can be derived by reversing the Pauling definition of electronegativity, but empirical corrections are needed to allow for extra strength of multiple oxygen or nitrogen bonding, as in... 

Several definitions of electronegativity have since been proposed and various methods for its evaluation suggested. A reliable compilation extensively used in discussing metallurgical behaviour is that by Teatum et al. (1968). 

This is true for our procedure for calculating partial atomic charges in a-bonded molecules (16). The method starts from Mulliken s definition of electronegativity, x> derived from atomic ionization potentials, IP, and electronegativities, EA (Equation 3)(17). 

Hinze et al. (1963) suggest that charge transfer in diatomic molecules obeys the principle of equality of energies involved in the process. If we adopt equation 1.31 as a definition of electronegativity and imagine that the amount of energy involved in the transfer of a fraction of charge dz from atom A to atom B is quantifiable as... 

The three polar molecules in the series are interesting because they all have anomalous directions to their dipole moments, i.e., the direction is different from that predicted by an elementary application of the idea of electronegativity, accepting the fact that there may be ambiguity in the definition of electronegativity for Ne. We will see how VB ideas interpret these anomalous dipole moments. 

We will not be concerned with the subtleties of chemical potential expressions in this work but simply use Eqn (17) as a definition of electronegativity [1]. 

E(Z, N) — E(Z, N— 1), that is from an ionization potential. Indeed it has already been seen in Section 7 that, for a neutral atom, n is in magnitude approximately half the ionization potential, for the case when the electron affinity is sufficiently small to be neglected. Mulliken s definition of electronegativity, namely... 

All this is in contradiction to the density functional definition of electronegativity as presented originally by Parr[36], where it is also inferred that the electronegativity for all the (natural) orbitals of the system should be the same. The discrepancy between these two different derivations and points of view[29,36] is still to be resolved. In addition, the global definition of electronegativity as promulgated within density functional theory, does not appear to be particularly useful, as it yields the same... 

Equation [33] is Mulliken s definition of electronegativity, so the linear coefficient in the Taylor series is the electronegativity of the atom. Mulliken s definition is consistent with other electronegativity scales. The second-order coefficient, j J, is the hardness of the atom, For semiconductors, the hardness is half the band gap, and r] is an important property in inorganic and acid-base chemistry. " Physically, IP - EA is the energy required to transfer an electron from one atom to another atom of the same type,... 

The definition of electronegativity, according to Mulliken, assumes its dependence on the valence state of atoms that allows one to reject the idea of a single EN for each atom independent of its hybridization. Thus, the necessity arises to take into account an orbital in which the valence electron is localized. 

This definition of hardness is related to Mulliken s definition of electronegativity, called absolute electronegativity by Pearson ... 

The method of electronegativity equalization is used to fix the charges, with Mulliken definition of electronegativity. This is related by Parr [175] to the chemical potential of an electron gas, using Kohn-Sham approximation in the framework of density functional theory. Hence, electronegativity equalization corresponds to equating chemical potentials. 

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