To validate these experimental results, we perform DFT calculations to determine Δ𝐺 + of ligand-M 2+ coordination interaction in stepwise manner beginning with a ML1 binding state (Methods). Each metal ion starts with binding six explicit water molecules in an octahedral arrangement as M(H2O)6. Histamine or imidazole ligands are sequentially added while displacing two or one water molecules respectively. The energy for each ML, ML2, ML3, and ML4 complex is computed as a sum of the ligand addition steps to reach the required binding coordination number. The results of the calculations for histamine (Fig. ) and imidazole (Fig. ) for the different M 2+ were in good agreement with the hierarchy obtained via viscosity measurements (Fig. ). For histamine, experiments and computation show that ML3 complexes follow a Ni 2+ > Cu 2+ > Zn 2+ hierarchy, and ML2 complexes follow a Cu 2+ > Zn 2+ > Ni 2+ hierarchy. For imidazole, experiments and computation show that ML4 complexes follow a Ni 2+ > Cu 2+ > Zn 2+ hierarchy, and ML2 complexes follow a Cu 2+ > Ni 2+ > Zn 2+ hierarchy.