Crystal structure of barium perchlorate anhydrate, Ba(ClO4)2, from laboratory X-ray powder data

The previously unknown crystal structure of barium perchlorate anhydrate, determined and refined from laboratory X-ray powder diffraction data, represents a new structure type. The title compound was obtained by heating hydrated barium perchlorate [Ba(ClO4)2·xH2O] at 423 Kin vacuofor 6 h. It crystallizes in the orthorhombic space groupFddd. The asymmetric unit contains one Ba (site symmetry 222 on special position 8a), one Cl (site symmetry 2 on special position 16f) and two O sites (on general positions 32h). The structure can be described as a three-dimensional polyhedral network resulting from the corner- and edge-sharing of BaO12polyhedra and ClO4tetrahedra. Each BaO12polyhedron shares corners with eight ClO4tetrahedra, and edges with two ClO4tetrahedra. Each ClO4tetrahedron shares corners with four BaO12polyhedra, and an edge with the other BaO12polyhedron.