Recent studies reveal that the ĪS,min is a means for rapidly predicting the relative reactivities of different carbon sites on the graphene model [70] and different CNT structures either with and without a Stone–Wales defect [68,69]. Saha and co-workers [69] indicated that the minimum values of ĪS(r) correlate well with the chemisorption energies of hydrogen and fluorine atom addition at the respective carbon sites.