The model could capture the basic Zr-O and intra-Zr6 Zr-Zr distances but gave overall a poor agreement and a significant misfit in the Zr-O distance. Using the dimer structure, the inter-Zr6 Zr-Zr distances are well described. By including the oxygen atoms from the coordinated acetates, a significant reduction in Rw is achieved and the Zr-O peak is now accurately fitted. By including the carbon atoms from the coordinated acetate, we obtain a decent fit, with an Rw = 0.14. The crystal structure of Zr12-acetate contains also hydrogen bonded ligands and co-crystallized DCM molecules. When the hydrogen bonded ligands are explicitly included, only a marginally better fit is obtained, see Figure . Alternatively, we added an exponentially decaying sinusoidal function as a second phase, resulting in a slightly (but significantly) better fit with Rw value 0.11, see Figure . This second phase describes disordered but still structured intensity and has previously been used to model solvent restructuring, or a regular array of high/low density regions. While it is gratifying to obtain an excellent fit for the data, we sought to determine whether we could distinguish the Zr12-acetate structure from other reported clusters structures (determined by single crystals XRD). We thus attempted to fit the experimental PDF of Zr12-acetate clusters with the reported structures of Zr4-methacrylate, Zr6-methacrylate, Zr6-acetate, Zr6-isobutyrate, Zr6-tert-butanoate and Zr12-propionate, see Figure . For these refinements, we removed the excess carbons in the structures to arrive at models with acetate ligands.