for the C atom parameters we observe similar trends in the performance as observed above for meta-substitution. The bestperforming methods are Hirshfeld (R 2 = 0.94), CM5 (R 2 = 0.86), and MBS-Mulliken (R Our computed parameters and results above were obtained for ground singlet state nitroarenes; however, we also computed parameters for the triplet excited state, which is the reactive intermediate involved in the cycloaddition (see Supporting