We employed the Atoms-in-Molecules (AIM) method to demonstrate the fingerprint of chemical interactions, which quantifies the electron density (ρi) at the bond critical points (BCPs) of intermolecular interactions . In this framework, covalent bonds, coordinate covalent bonds and hydrogen bonds (highly polarized interactions), and weak electrostatic interactions show ρi values of ~0.50-0.10, 0.10-0.04 ≤0.01 e/Bohr 3 , respectively. AIM, Mayer bond orders, Mulliken population analyses, and wavefunction analyses were performed in the Multiwfn 3.7 program . An orbital picture of the bonding was obtained through the natural bond orbital NBO module in Gaussian16 at the same level of theory .