Materials Data on Ca3(PO4)2 by Materials Project

Abstract

Ca3(PO4)2 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to four O2- atoms. There are two shorter (2.37 Å) and two longer (2.43 Å) Ca–O bond lengths. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six PO4 tetrahedra and edges with two equivalent CaO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.28–2.59 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with six equivalent CaO6 octahedra. The corner-sharing octahedra tilt angles range from 47–52°. There is two shorter (1.55 Å) and two longer (1.56 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with six equivalent CaO6 octahedra. The corner-sharing octahedra tilt angles range from 37–57°. There is two shorter (1.52 Å) and two longer (1.59 Å) P–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Ca2+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ca2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom.