DOI: 10.17188/1751008
title: Materials Data on Ca19Mg(AsO4)14 by Materials Project

description: Ca19Mg(AsO4)14 is Esseneite-like structured and 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 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.63 Å. In the second Ca site, Ca is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.61 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 2.37–2.87 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 2.40–2.90 Å. In the fifth 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 2.39–3.01 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 2.40–2.98 Å. In the seventh Ca site, Ca is bonded to six O atoms to form distorted CaO6 octahedra that share corners with six AsO4 tetrahedra. There are three shorter (2.28 Å) and three longer (2.30 Å) Ca–O bond lengths. Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six AsO4 tetrahedra. There are three shorter (2.11 Å) and three longer (2.13 Å) Mg–O bond lengths. There are six inequivalent As sites. In the first As site, As is bonded to four O atoms to form AsO4 tetrahedra that share a cornercorner with one MgO6 octahedra. The corner-sharing octahedral tilt angles are 48°. There is two shorter (1.71 Å) and two longer (1.73 Å) As–O bond length. In the second As site, As is bonded to four O atoms to form AsO4 tetrahedra that share a cornercorner with one CaO6 octahedra. The corner-sharing octahedral tilt angles are 55°. There are a spread of As–O bond distances ranging from 1.70–1.73 Å. In the third As site, As is bonded to four O atoms to form AsO4 tetrahedra that share a cornercorner with one CaO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of As–O bond distances ranging from 1.70–1.74 Å. In the fourth As site, As is bonded to four O atoms to form AsO4 tetrahedra that share a cornercorner with one MgO6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of As–O bond distances ranging from 1.70–1.73 Å. In the fifth As site, As is bonded in a tetrahedral geometry to four O atoms. There is three shorter (1.73 Å) and one longer (1.75 Å) As–O bond length. In the sixth As site, As is bonded in a tetrahedral geometry to four O atoms. There is three shorter (1.72 Å) and one longer (1.74 Å) As–O bond length. There are twenty inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to two Ca and one As atom. In the second O site, O is bonded in a 4-coordinate geometry to three Ca and one As atom. In the third O site, O is bonded in a 4-coordinate geometry to two equivalent Ca, one Mg, and one As atom. In the fourth O site, O is bonded in a distorted tetrahedral geometry to three Ca and one As atom. In the fifth O site, O is bonded in a distorted tetrahedral geometry to three Ca and one As atom. In the sixth O site, O is bonded in a distorted trigonal planar geometry to two Ca and one As atom. In the seventh O site, O is bonded in a 3-coordinate geometry to two Ca and one As atom. In the eighth O site, O is bonded in a single-bond geometry to one As atom. In the ninth O site, O is bonded in a single-bond geometry to one As atom. In the tenth O site, O is bonded in a 4-coordinate geometry to three Ca and one As atom. In the eleventh O site, O is bonded in a 4-coordinate geometry to three Ca and one As atom. In the twelfth O site, O is bonded in a 3-coordinate geometry to three Ca and one As atom. In the thirteenth O site, O is bonded in a 4-coordinate geometry to three Ca and one As atom. In the fourteenth O site, O is bonded in a 4-coordinate geometry to three Ca and one As atom. In the fifteenth O site, O is bonded in a 4-coordinate geometry to three Ca and one As atom. In the sixteenth O site, O is bonded in a 4-coordinate geometry to two equivalent Ca, one Mg, and one As atom. In the seventeenth O site, O is bonded in a 4-coordinate geometry to three Ca and one As atom. In the eighteenth O site, O is bonded in a 4-coordinate geometry to three Ca and one As atom. In the nineteenth O site, O is bonded in a 4-coordinate geometry to three Ca and one As atom. In the twentieth O site, O is bonded in a 3-coordinate geometry to two Ca and one As atom.