“…81 In addition, Δ 2 ρ (BCP) > 0.1 is the ionic bond, Δ 2 ρ (BCP) ≈ 0.1 is the covalent bond, and Δ 2 ρ (BCP) ≦ 0.01 is the van der Waals and HB; | V ( r )|/ G ( r ) < 1, 1 < | V ( r )|/ G ( r ) > 2, and | V ( r )|/ G ( r ) > 2 represent the non-covalent, weakly covalent, and covalent interactions, respectively. 82 As can be seen from Fig. 5, there are two types of interactions between the 5Fu drug and MB11N12 nanocages, one is O–Al and O–Ga ionic bonds and the other is O–B and N–H covalent bonds.…”