Materials Data on CaSn4(PO4)6 by Materials Project

Abstract

CaSn4(PO4)6 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Ca2+ is bonded in a distorted hexagonal planar geometry to six equivalent O2- atoms. All Ca–O bond lengths are 2.53 Å. There are two inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with six equivalent PO4 tetrahedra. There are three shorter (2.04 Å) and three longer (2.07 Å) Sn–O bond lengths. In the second Sn4+ site, 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 (2.11 Å) Sn–O bond lengths. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four SnO6 octahedra. The corner-sharing octahedra tilt angles range from 31–48°. 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 bent 150 degrees geometry to one Sn4+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sn4+ 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 3-coordinate geometry to one Ca2+, one Sn4+, and one P5+ atom.