Atomic and Electronic Structure of Graphene Oxide*

We have investigated the atomic structure of graphene oxide by DFT calculations. Our spin restricted ab-initio density functional calculations have shown that the oxygen link to the graphene basal plane using epoxide bonds. The flat graphene sheets are found to deform by buckling due to formation of C -- O -- C linkages normal to the plane of the graphene sheets. The calculations were compared with x-ray diffraction and x-ray spectroscopic measurements. Tentative models of the structure are proposed based on the combined DFT and experimental data.