The pyrochlore-type molybdate Pr1.37Ca0.63Mo2O7

Praseodymium calcium dimolybdenum hepta-oxide, Pr(1.37)Ca(0.63)Mo(2)O(7), crystallizes in the cubic pyrochlore-type structure. In the crystal structure, MoO(6) octa-hedra are linked together by common corners, forming a three-dimensional [Mo(2)O(6)] network. The Pr and Ca atoms and the remaining O atoms are located in the voids of the [Mo(2)O(6)] network. The Pr and Ca atoms are distributed statistically over the same 16c crystallographic position with site-occupancy factors of 0.684 (3) and 0.316 (3), respectively. They are surrounded by eight O atoms forming a ditrigonal scalenohedron. All atoms lie on special positions. The (Pr, Ca) and Mo atoms are, respectively in the 16c and 16d positions with m symmetry, and the O atoms in the 48f or 8a positions with mm or 3m site symmetry, respectively.