which leads to the interpretation of an electrophilic ligand immersed in an idealized zerotemperature free electron sea of zero electronegativity χ S = 0 and vanishing chemical hardness η S = 0 36 . In presence of enough electrons to saturate the considered molecule in terms of full charge transfer ∆N max = χ Z /η Z 36 , the reaction energy according to Eqn. ( ) can be written as