The AIM analysis allows assessing the binding mechanism from the values of electron density (i) at intermolecular bond critical points [BCPs, points in space at which the first derivatives of the electron density vanish (r)=0, Fig. ]. Accordingly, the covalent complexes e/Bohr 3 ), which are associated with weak electrostatic interactions (blue numbers in Fig. ). In this regard, EDA shows the electrostatic term (EELEC) reaches the third largest contribution to the stability (17-31%). The electrostatic contribution emerges from the electron-sufficient carbon atoms of fullerenes, which acquire a negative charge that electrostatically attracts the electron-Fig. . Electron density at the bond critical points of intermolecular interactions (I, in e/Bohr 3 ) for representative Phos-Fullerene complexes.