DOI: 10.17188/1284264
title: Materials Data on Ca3(PO4)2 by Materials Project

description: Ca3(PO4)2 crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are nine inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a distorted T-shaped geometry to three equivalent O2- atoms. All Ca–O bond lengths are 2.23 Å. In the second Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ca–O bond distances ranging from 2.26–2.45 Å. In the third Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.25–2.83 Å. In the fourth Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 pentagonal pyramids that share corners with four PO4 tetrahedra. There are a spread of Ca–O bond distances ranging from 2.29–2.67 Å. In the fifth Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.26–2.78 Å. In the sixth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.26–2.69 Å. In the seventh Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.26–2.85 Å. In the eighth Ca2+ site, Ca2+ is bonded in a 3-coordinate geometry to three equivalent O2- atoms. All Ca–O bond lengths are 2.26 Å. In the ninth Ca2+ site, Ca2+ is bonded in a 3-coordinate geometry to six O2- atoms. There are three shorter (2.34 Å) and three longer (2.81 Å) Ca–O bond lengths. There are six inequivalent P5+ sites. In the first P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There is one shorter (1.52 Å) and three longer (1.57 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 two equivalent CaO6 pentagonal pyramids. There are a spread of P–O bond distances ranging from 1.55–1.58 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CaO6 pentagonal pyramid. There are a spread of P–O bond distances ranging from 1.54–1.59 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent CaO6 pentagonal pyramids. There is one shorter (1.55 Å) and three longer (1.56 Å) P–O bond length. In the fifth P5+ site, P5+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of P–O bond distances ranging from 1.55–1.68 Å. In the sixth P5+ site, P5+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of P–O bond distances ranging from 1.55–1.69 Å. There are twenty inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted tetrahedral geometry to three equivalent Ca2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+, one P5+, and one O2- atom. The O–O bond length is 1.52 Å. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and one O2- atom. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Ca2+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted single-bond geometry to three Ca2+ and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+ and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Ca2+ and one O2- atom. The O–O bond length is 1.51 Å. In the seventeenth O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+, one P5+, and one O2- atom. In the eighteenth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Ca2+ and one P5+ atom. In the twentieth O2- site, O2- is bonded in a distorted single-bond geometry to three Ca2+ and one P5+ atom.