DOI: 10.17188/1740197
title: Materials Data on Ca19Mg2(PO4)14 by Materials Project

description: Ca19Mg2(PO4)14 crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are seven inequivalent Ca sites. In the first Ca site, Ca is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Ca–O bond distances ranging from 2.38–2.71 Å. In the second Ca site, Ca is bonded in a 9-coordinate geometry to eight O atoms. There are a spread of Ca–O bond distances ranging from 2.44–2.71 Å. In the third Ca site, Ca is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Ca–O bond distances ranging from 2.37–2.73 Å. In the fourth Ca site, Ca is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Ca–O bond distances ranging from 2.36–2.71 Å. In the fifth Ca site, Ca is bonded in a 7-coordinate geometry to eight O atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.94 Å. In the sixth Ca site, Ca is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Ca–O bond distances ranging from 2.36–2.84 Å. In the seventh Ca site, Ca is bonded in a 3-coordinate geometry to six O atoms. There are three shorter (2.38 Å) and three longer (2.65 Å) Ca–O bond lengths. There are two inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six PO4 tetrahedra. All Mg–O bond lengths are 2.10 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six PO4 tetrahedra. There are three shorter (2.09 Å) and three longer (2.11 Å) Mg–O bond lengths. There are six inequivalent P sites. In the first P site, P is bonded in a tetrahedral geometry to four O atoms. There is one shorter (1.52 Å) and three longer (1.57 Å) P–O bond length. In the second P site, P is bonded in a tetrahedral geometry to four O atoms. There is three shorter (1.55 Å) and one longer (1.57 Å) P–O bond length. In the third P site, P is bonded to four O atoms to form PO4 tetrahedra that share a cornercorner with one MgO6 octahedra. The corner-sharing octahedral tilt angles are 39°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. In the fourth P site, P is bonded to four O atoms to form PO4 tetrahedra that share a cornercorner with one MgO6 octahedra. The corner-sharing octahedral tilt angles are 44°. There are a spread of P–O bond distances ranging from 1.54–1.58 Å. In the fifth P site, P is bonded to four O atoms to form PO4 tetrahedra that share a cornercorner with one MgO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There is three shorter (1.55 Å) and one longer (1.56 Å) P–O bond length. In the sixth P site, P is bonded to four O atoms to form PO4 tetrahedra that share a cornercorner with one MgO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There is three shorter (1.55 Å) and one longer (1.56 Å) P–O bond length. There are twenty inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to three equivalent Ca and one P atom. In the second O site, O is bonded in a distorted tetrahedral geometry to three equivalent Ca and one P atom. In the third O site, O is bonded in a distorted single-bond geometry to three Ca and one P atom. In the fourth O site, O is bonded in a 1-coordinate geometry to three Ca and one P atom. In the fifth O site, O is bonded in a 1-coordinate geometry to three Ca and one P atom. In the sixth O site, O is bonded in a 3-coordinate geometry to two Ca and one P atom. In the seventh O site, O is bonded in a 1-coordinate geometry to three Ca and one P atom. In the eighth O site, O is bonded in a 4-coordinate geometry to three Ca and one P atom. In the ninth O site, O is bonded in a 4-coordinate geometry to three Ca and one P atom. In the tenth O site, O is bonded in a 3-coordinate geometry to two Ca and one P atom. In the eleventh O site, O is bonded in a 1-coordinate geometry to three Ca and one P atom. In the twelfth O site, O is bonded in a 1-coordinate geometry to three Ca and one P atom. In the thirteenth O site, O is bonded in a 1-coordinate geometry to three Ca and one P atom. In the fourteenth O site, O is bonded in a 4-coordinate geometry to three Ca and one P atom. In the fifteenth O site, O is bonded in a 1-coordinate geometry to three Ca and one P atom. In the sixteenth O site, O is bonded in a 1-coordinate geometry to three Ca and one P atom. In the seventeenth O site, O is bonded in a 4-coordinate geometry to two equivalent Ca, one Mg, and one P atom. In the eighteenth O site, O is bonded in a 4-coordinate geometry to two equivalent Ca, one Mg, and one P atom. In the nineteenth O site, O is bonded in a 4-coordinate geometry to two equivalent Ca, one Mg, and one P atom. In the twentieth O site, O is bonded in a 4-coordinate geometry to two equivalent Ca, one Mg, and one P atom.