Crystal structure of calcium perchlorate anhydrate, Ca(ClO(4))(2), from laboratory powder X-ray diffraction data

The crystal structure of calcium perchlorate anhydrate was determined from laboratory X-ray powder diffraction data. The title compound was obtained by heating hydrated calcium perchlorate [Ca(ClO(4))(2)·xH(2)O] at 623 K in air for 12 h. It crystallizes in the ortho­rhom­bic space group Pbca and is isotypic with Ca(AlD(4))(2). The asymmetric unit contains one Ca, two Cl and eight O sites, all on general sites (Wyckoff position 8c). The crystal structure consists of isolated ClO(4) (−) tetra­hedra and Ca(2+) cations. The Ca(2+) cation is coordinated by eight O atoms of eight symmetry-related ClO(4) (−) tetra­hedra within a distorted square-anti­prismatic environment.