Analysis of the nature of the interactions through NBO, QTAIM, and NCE methods points to an enhancement of dative covalent interactions in tetrahedral environments, which decrease in the following order: im-idazole > acetate > water. However, pure electrostatic NCE point charge models favour octahedral complexes with a larger number of acetates, with electrostatic interactions decreasing in the following order: acetate > imidazole > water. Thus, there is a balance between dative covalent interactions, electrostatics, and partial desolvation penalty which explains the preferred trends in coordination with tetrahedral [Zn(Im) 3 (Ac) 1 ] + and [Zn(Im) 2 (Ac) 2 ] clusters. These coordinations show a mixture of imidazole/acetate ligands and an arrangement that optimize the dative covalent interactions with imidazoles, and the electrostatic interactions with a few numbers of acetates, maintaining a reduced coulombic repulsion between negatively-charged residues.