Dr. Antonio Cammarata reports with Professor Rondinelli in their new article, Covalent dependence of octahedral rotations in orthorhombic perovskite oxides, on how the dependence of octahedral rotations in orthorhombic ABO3 perovskite oxides depends on changes in metal-oxygen bond covalency. While the composition dependence is well understood through the use of tolerance factor arguments, this first-principles study identifies that the more covalent the metal–oxygen bond, the less distorted is the structure and the more important the long-range inter-octahedral interactions. This result reveals that one can indirectly tune the B-O bond covalency by A-cation induced BO6 rotations independent of ionic size in perovskites, facilitating design of targeted bonding interactions in artificial materials.