Thereafter, the structures of possible Cu-malonic acid complexes with different binding stoichiometries (Table , entries 2 and 3) were modeled and the associated free energies were recorded. The binding energies of all modeled complexes were determined and the Cu-malonic acid complex with the 2:1 malonic acid-Cu binding stoichiometry (Table , entry 3) was found to be the most favourable as it had the lowest binding energy of the complexes modeled.