The equilibrium structure of the Be(1120) surface has been determined using LEED I - V analysis. This surface exhibits a stable (1 × 3) reconstruction over the range of temperatures investigated (100–720 K) where the surface starts to disorder. The equilibrium structure consists of a missing-row reconstruction in which every third surface chain of the bulk-terminated structure is absent. The experimentally determined structure is at odds with first-principles calculations, which favor a relaxed but unreconstructed bulk termination.
