The DFT calculations were performed using Gridbased Projector Augment Wave (GPAW) , assisted by the Atomic Simulation Environment (ASE) . The employed functional was RPBE as it describes strong chemical interactions very well . This makes it a decent choice for the study of oxygen binding energies in and on the rutile surface. The rutile RuO 2 slab was made up of four atomic layers with the bottom two emulating bulk by being positionally constrained. The structure was replicated two times in the y direction to produce the structure shown in fig. . To avoid unwanted selfinteraction, a vacuum was introduced above and below the structure. All other structures were created by substitution of atoms in this slab and removal/addition of surface adsorbates. Due to the magnetic properties of nickel, the calculations including nickel were spin polarized. For Brillouin zone sampling, a k-point mesh of (3,2,1) was used. The grid-spacing used for the calculations was 0.20 Å and the relaxation was terminated when the sum of forces in the system went below 0.05 eV Å-1 . Structures and scripts are available in the electronic supplementary material at link: -electrocatalysis/katladb/loer-runio2/