Materials Data on SrFeSn(PO4)3 by Materials Project
SrFeSn(PO4)3 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a hexagonal planar geometry to six equivalent O2- atoms. All Sr–O bond lengths are 2.66 Å. In the second Sr2+ site, Sr2+ is bonded in a distorted hexagonal planar geometry to six equivalent O2- atoms. All Sr–O bond lengths are 2.59 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent PO4 tetrahedra. There are three shorter (1.99 Å) and three longer (2.06 Å) Fe–O bond lengths. Sn4+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with six equivalent PO4 tetrahedra. There are three shorter (2.03 Å) and three longer (2.09 Å) Sn–O bond lengths. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent FeO6 octahedra and corners with two equivalent SnO6 octahedra. The corner-sharing octahedra tilt angles range from 34–38°. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Sr2+, one Sn4+, and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+, one Fe3+, and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Sn4+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one P5+ atom.