Materials Data on CaFeSn(PO4)3 by Materials Project
CaFeSn(PO4)3 crystallizes in the trigonal R3c space group. The structure is three-dimensional. Ca2+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are three shorter (2.37 Å) and three longer (2.48 Å) Ca–O bond lengths. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent PO4 tetrahedra. There are three shorter (1.96 Å) and three longer (2.09 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 (2.02 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 26–43°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+, one Sn4+, and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Fe3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Sn4+ and one P5+ atom.