Materials Data on Sr2P7Br by Materials Project

Abstract

Sr2P7Br crystallizes in the cubic P2_13 space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 10-coordinate geometry to seven P+0.43- and three equivalent Br1- atoms. There are a spread of Sr–P bond distances ranging from 3.16–3.67 Å. All Sr–Br bond lengths are 3.54 Å. In the second Sr2+ site, Sr2+ is bonded in a 1-coordinate geometry to twelve P+0.43- and one Br1- atom. There are a spread of Sr–P bond distances ranging from 3.15–3.40 Å. The Sr–Br bond length is 3.16 Å. There are three inequivalent P+0.43- sites. In the first P+0.43- site, P+0.43- is bonded to one Sr2+ and three equivalent P+0.43- atoms to form PSrP3 tetrahedra that share corners with three equivalent PSr3P2 trigonal bipyramids and corners with three equivalent BrSr4 trigonal pyramids. All P–P bond lengths are 2.19 Å. In the second P+0.43- site, P+0.43- is bonded to three Sr2+ and two P+0.43- atoms to form distorted PSr3P2 trigonal bipyramids that share a cornercorner with one PSrP3 tetrahedra, corners with six equivalent PSr3P2 trigonal bipyramids, corners with three equivalent BrSr4 trigonal pyramids, edges with four equivalent PSr3P2 trigonal bipyramids, and an edgeedge with one BrSr4 trigonal pyramid. The P–P bond length is 2.17 Å. In the third P+0.43- site, P+0.43- is bonded in a 6-coordinate geometry to three Sr2+ and three P+0.43- atoms. Both P–P bond lengths are 2.29 Å. Br1- is bonded to four Sr2+ atoms to form BrSr4 trigonal pyramids that share corners with three equivalent PSrP3 tetrahedra, corners with nine equivalent PSr3P2 trigonal bipyramids, corners with six equivalent BrSr4 trigonal pyramids, and edges with three equivalent PSr3P2 trigonal bipyramids.