DOI: 10.17188/1731278
title: Materials Data on CaMg14CO16 by Materials Project

description: CaMg14CO16 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.15 Å) and four longer (2.26 Å) Ca–O bond lengths. There are five inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with two equivalent MgO6 octahedra, corners with two equivalent CO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.03 Å) and four longer (2.15 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent CaO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Mg–O bond distances ranging from 2.10–2.20 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent CaO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Mg–O bond distances ranging from 2.10–2.20 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent CO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.12–2.18 Å. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent MgO6 octahedra, an edgeedge with one CaO6 octahedra, an edgeedge with one CO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–4°. There are a spread of Mg–O bond distances ranging from 2.10–2.19 Å. C2+ is bonded to six O2- atoms to form CO6 octahedra that share corners with two equivalent CO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.14 Å) and two longer (2.15 Å) C–O bond lengths. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ca2+ and five Mg2+ atoms to form a mixture of corner and edge-sharing OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the second O2- site, O2- is bonded to five Mg2+ and one C2+ atom to form a mixture of corner and edge-sharing OMg5C octahedra. The corner-sharing octahedra tilt angles range from 0–1°. Both O–Mg bond lengths are 2.15 Å. In the third O2- site, O2- is bonded to five Mg2+ and one C2+ atom to form a mixture of corner and edge-sharing OMg5C octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are two shorter (2.10 Å) and two longer (2.15 Å) O–Mg bond lengths. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. In the fifth O2- site, O2- is bonded to two equivalent Ca2+ and four Mg2+ atoms to form OCa2Mg4 octahedra that share corners with six OCa2Mg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the sixth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OCa2Mg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the seventh O2- site, O2- is bonded to four equivalent Mg2+ and two equivalent C2+ atoms to form OMg4C2 octahedra that share corners with six OMg6 octahedra and edges with twelve OMg5C octahedra. The corner-sharing octahedral tilt angles are 0°. In the eighth O2- site, O2- is bonded to one Ca2+ and five Mg2+ atoms to form a mixture of corner and edge-sharing OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. Both O–Mg bond lengths are 2.19 Å. In the ninth O2- site, O2- is bonded to five Mg2+ and one C2+ atom to form a mixture of corner and edge-sharing OMg5C octahedra. The corner-sharing octahedra tilt angles range from 0–1°. The O–Mg bond length is 2.15 Å. In the tenth O2- site, O2- is bonded to five Mg2+ and one C2+ atom to form a mixture of corner and edge-sharing OMg5C octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are two shorter (2.10 Å) and three longer (2.15 Å) O–Mg bond lengths.