where r cov i , r cov j are the covalent radii of atoms i, j, and α bond is a constant exceeding 1 (set to 1.25 in this study). We define A r and A p as sets of atom pairs bonded only in the reactant and product, respectively. A r,i and A p,i represent subsets of A r and A p containing pairs that include atom i. An atom i is termed a pivot atom if |A r,i | > 0 and |A p,i | > 0 (Figure ), indicating both bond breaking and formation occur around this atom. In particular, an atom ), indicating exactly one bond to be broken and one to be formed around this atom. The pairs of atom pairs depicted in Figure are likely to exhibit varying degrees of correlation. In Figure , where no pivot atom is present, the correlation is likely weaker due to the spatial separation of the atom pairs. In contrast, cases involving pivot atoms (Figures and) are expected to show stronger correlations to prevent pivot atom isolation. In configurations with multiple pairs of pairs mediated by a pivot atom (Figure ), strong correlation in at least one pair is enough, allowing for weaker correlations among other pairs.