Materials Data on Sr3W2O9 by Materials Project

Abstract

Sr3W2O9 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to five O2- atoms to form distorted SrO5 trigonal bipyramids that share corners with four WO4 tetrahedra, a cornercorner with one SrO5 trigonal bipyramid, and edges with two equivalent SrO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.35–2.62 Å. In the second Sr2+ site, Sr2+ is bonded to six O2- atoms to form SrO6 octahedra that share corners with two equivalent SrO6 octahedra, corners with four WO4 tetrahedra, and edges with four SrO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 62°. There are a spread of Sr–O bond distances ranging from 2.37–2.65 Å. In the third Sr2+ site, Sr2+ is bonded to five O2- atoms to form distorted SrO5 trigonal bipyramids that share corners with four WO4 tetrahedra, a cornercorner with one SrO5 trigonal bipyramid, and edges with two equivalent SrO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.35–2.63 Å. There are two inequivalent W6+ sites. In the first W6+ site, W6+ is bonded to four O2- atoms to form WO4 tetrahedra that share corners with two equivalent SrO6 octahedra and corners with four SrO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 48°. There are a spread of W–O bond distances ranging from 1.80–1.83 Å. In the second W6+ site, W6+ is bonded to four O2- atoms to form WO4 tetrahedra that share corners with two equivalent SrO6 octahedra and corners with four SrO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 43°. There is two shorter (1.80 Å) and two longer (1.83 Å) W–O bond length. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded to four Sr2+ atoms to form corner-sharing OSr4 tetrahedra. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Sr2+ and one W6+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Sr2+ and one W6+ atom. In the fourth O2- site, O2- is bonded in a linear geometry to one Sr2+ and one W6+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sr2+ and one W6+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Sr2+ and one W6+ atom. In the seventh O2- site, O2- is bonded in a linear geometry to one Sr2+ and one W6+ atom.