Scheme 1 presents the classic reaction mechanism of the electrophilic bromination of nitrobenzene, which first proceeds through a cationic intermediate (the so-called Wheland intermediate) PhNO 2 -Br + , that undergoes subsequent deprotonation to afford the product. In this work, we focus on the cavity modification of the energies of these positively charged reaction intermediates PhNO 2 -Br + . This molecule is accepted as the quasi-stable intermediate species in the kinetics of the bromination of nitrobenzene, and the site selectivity of halogenations of aryl species is largely dictated by this intermediate. However, recent experimental and theoretical explorations have demonstrated that other pathways, such as an additionelimination route, maybe more favored under certain conditions. Outside the cavity, the meta-intermediate is the most stable for nitrobenzene and provides nearly 100% selectivity due to a favorable set of possible resonance structures. On the other hand, the paraand ortho-substituted products are not observed due to the presence of high-energy resonance structures. In the case of bromination outside of the cavity, which corresponds to the A 0 = 0.0 a.u. and ω c = 0.0 eV case in Eq. 2, the meta-substituted intermediate species is more thermodynamically stable compared to the ortho-and para-species by roughly 2 and 5 kcal/mol, respectively, confirming this classic reaction mechanism.