Materials Data on Sr3(AsO4)2 by Materials Project

Abstract

Sr3(AsO4)2 crystallizes in the monoclinic P2_1/c 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 five AsO4 tetrahedra, a cornercorner with one SrO5 trigonal bipyramid, an edgeedge with one SrO6 octahedra, and an edgeedge with one SrO5 trigonal bipyramid. There are a spread of Sr–O bond distances ranging from 2.43–2.52 Å. In the second Sr2+ site, Sr2+ is bonded to five O2- atoms to form SrO5 trigonal bipyramids that share corners with two equivalent SrO6 octahedra, corners with five AsO4 tetrahedra, a cornercorner with one SrO5 trigonal bipyramid, and an edgeedge with one SrO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 66–76°. There are a spread of Sr–O bond distances ranging from 2.35–2.52 Å. In the third Sr2+ site, Sr2+ is bonded to six O2- atoms to form distorted SrO6 octahedra that share corners with four AsO4 tetrahedra, corners with two equivalent SrO5 trigonal bipyramids, an edgeedge with one SrO6 octahedra, an edgeedge with one AsO4 tetrahedra, and an edgeedge with one SrO5 trigonal bipyramid. There are a spread of Sr–O bond distances ranging from 2.45–2.78 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with three equivalent SrO6 octahedra and corners with five SrO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 47–55°. There is one shorter (1.72 Å) and three longer (1.73 Å) As–O bond length. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share a cornercorner with one SrO6 octahedra, corners with five SrO5 trigonal bipyramids, and an edgeedge with one SrO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of As–O bond distances ranging from 1.71–1.73 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two Sr2+ and one As5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Sr2+ and one As5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Sr2+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two Sr2+ and one As5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Sr2+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Sr2+ and one As5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Sr2+ and one As5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Sr2+ and one As5+ atom.