The resulting binding energies are -426.94 kJmol -1 and -575.84 kJmol -1 for g 2,2 and g 4,2 , respectively. The latter case (missing linker and O-vacancies) is particularly interesting. GO in water is in equilibrium with mono-and dihydrated forms. As described by Ohshima et al., the conversion of GO to GA in water likely starts with the formation of a mono-hydrated GO, which binds to Lewis acids, followed by an internal 1,2 hydride shift to produce the final product. Due to the sensitivity of Zr-Zr distances to changes in the surface chemistry of distorted clusters, we expected substrate binding to appear as shifts in the PDF. DFT simulations showed that GO binding forms new oxygen bridges, bringing neighboring Zr cus -Zr cus sites closer, reducing the pair distance from 3.96 to 3.60 Å (Figure ). In Figure , the red dotted line represents the PDF of g 4,2 , whereas the blue dotted line represents the PDF of the same cluster after binding GO. We see that the average Zr-Zr distances in the simulated PDFs change significantly after binding GO. Therefore, we conducted in situ PDF experiments on aDUT-67 after soaking in a GO solution. The experimental PDF of the soaked sample confirmed this shift, with the elongated Zr cus -Zr cus peak at 3.94 Å almost disappearing and a new broad peak centered at 3.475 Å emerging (solid blue line). The broadness of the peak suggests a significant disorder in the Zr-Zr atom pairs.