Defining Absolute Aromaticity by Chemical Reactivity

it seems natural to compare the two stages of a molecular bonding, for a given reactivity index, which through their difference should reveal the excess chemical information responsible for the stability of that molecular system. In other words, by subtracting the already formed molecular orbital (MO) information from that obtained by superposition of atomic information in bonding H the present discussion follows (Putz, 2010b) 

When the electronegativity index is considered in Eq. (4.18) the electronegativity-based absolute aromaticity is obtained with the working form 

FIGURE 4.5 Heuristic representation of the concept of absolute aromaticity (for the benzene pattern) as the stabilization difference of a given index of reactivity between atoms-in-molecule and molecular orbitals bonding configurations (Putz, 2010b). 

Instead, when chemical hardness based absolute aromaticity is particularized out of the general definition (4.18) with the help of AIM and CFD Eqs. (3.248) and (3.376), respectively 

Quantum Nanochemistry—Volume III Quantum Molecules and Reactivity 

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