As eluded to earlier, several studies using DFT-based optimizations showed that the most stable 1:1 Zr 4+ -DFO complex is with six oxygen atoms stemming from the DFO molecule coordinated to Zr 4+ . Our results, however, paint a different picture when temperature and solvent are explicitly included. One the one hand, there have been numerous studies of molecular systems (regarding for example the binding between ligands and proteins) showing that both solvent and temperature can have a drastic effect on both the binding mechanisms and subsequently thermodynamics. Specific solvation of water in response to the presence of a solute such as a hydrophobic moiety or a dipole or charge re-distribution is known to play a critical role in a wide range of physical and chemical processes. At the same time, we do not explicitly include electronic effects in our model.