The crystal structure of α-SrMnO3

α-SrMnO₃ crystallizes in the hexagonal system with unit-cell dimensions a = 5.454(1) Å, c = 9.092(2)Å, space group $\text{P6}{}_3\text{mmc}\text{, Z = 4}$. The structure was solved by the heavy-atom method; of 404 unique reflections measured by counter method, 203 that obeyed the condition |F₀| ≥ 3σ (|F₀|) were used in the refinement to a conventional R value of 0.043. The structure consists of four close-packed SrO₃ layers in an ABAC stacking sequence along the hexagonal c axis. Oxygen octahedra containing Mn⁴⁺ are grouped into face-sharing pairs linked by corner sharing within the cubically stacked “A” layer.