This archive provides the data set created for the article "Theoretical investigations on surface stabilities of CuBi2O4 and CuFeO2". The work was funded by the DFG through the priority program SPP-2370 (project id 502202153). The directory is divided into four main folders: Bulk, PBE, PBE+U, and Surfaces. The folder structure is split into bulk and surface calculations for each material (CuFeO2: CFO and CuBi2O4: CBO). Beyond that, the folders for the surfaces are divided further into the surfaces (100), (110), and (001) for CBO, (111), (110), (001), (100), and (012) for CFO. Within these folders, there are additional folders for each investigated surface termination. The Bulk folder stores all optimization data required to calculate the Gibbs free energy of formation for binary metal oxides. This input data was used to generate the thermodynamic stability regions for the ternary copper oxides. The folders PBE and PBE+U create the data for the bulk properties of CBO and CFO, depending on the Hubbard U parameter. The folder Surface contains data for the geometry optimizations, Bader charges, and density of states for all investigated surfaces and their terminations of CBO and CFO. The Bader charges are calculated within the "SP_vaspkit" folders and the data for the density of states is calculated within the folders "vaspkit_band_k" or "band_vaspkit".