Materials Data on Sr2P7I by Materials Project

Abstract

Sr2P7I 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 7-coordinate geometry to twelve P+0.43- and one I1- atom. There are a spread of Sr–P bond distances ranging from 3.20–3.39 Å. The Sr–I bond length is 3.39 Å. In the second Sr2+ site, Sr2+ is bonded in a 7-coordinate geometry to four P+0.43- and three equivalent I1- atoms. There are one shorter (3.18 Å) and three longer (3.24 Å) Sr–P bond lengths. All Sr–I bond lengths are 3.59 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 square pyramids and corners with three equivalent ISr4 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 square pyramids that share corners with six equivalent PSr3P2 square pyramids, a cornercorner with one PSrP3 tetrahedra, corners with three equivalent ISr4 trigonal pyramids, edges with four equivalent PSr3P2 square pyramids, and an edgeedge with one ISr4 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 5-coordinate geometry to two equivalent Sr2+ and three P+0.43- atoms. Both P–P bond lengths are 2.29 Å. I1- is bonded to four Sr2+ atoms to form ISr4 trigonal pyramids that share corners with nine equivalent PSr3P2 square pyramids, corners with three equivalent PSrP3 tetrahedra, corners with six equivalent ISr4 trigonal pyramids, and edges with three equivalent PSr3P2 square pyramids.