Atomic geometry of steps on metal-oxide single crystals

The concepts of coordinative unsaturation and excess surface charge are used to predict which atomic geometries are likely to be most stable along step edges on metal-oxide single crystals. The specific case of steps on Fe3O4(1 1 1) is considered in detail, and two step structures are identified as having the lowest coordinative unsaturation and excess charge/step unit cell. This approach to step stability should be applicable to other crystal structures having both ionic and covalent components to their interatomic bonding.