DOI: 10.17188/1685730
title: Materials Data on CeMg30BO32 by Materials Project

description: Mg30CeBO32 is Molybdenum Carbide MAX Phase-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are eight inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent CeO6 octahedra, corners with four MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.02–2.18 Å. In the second Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.01–2.18 Å. In the third Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.13 Å) and two longer (2.15 Å) Mg–O bond lengths. In the fourth Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.14 Å) and two longer (2.17 Å) Mg–O bond lengths. In the fifth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CeO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–6°. There are a spread of Mg–O bond distances ranging from 2.07–2.26 Å. In the sixth Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. There are a spread of Mg–O bond distances ranging from 2.14–2.18 Å. In the seventh Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CeO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–4°. There are a spread of Mg–O bond distances ranging from 2.09–2.22 Å. In the eighth Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–9°. There are two shorter (2.15 Å) and four longer (2.17 Å) Mg–O bond lengths. Ce is bonded to six O atoms to form CeO6 octahedra that share corners with four equivalent MgO6 octahedra and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.22 Å) and four longer (2.30 Å) Ce–O bond lengths. B is bonded in a linear geometry to two equivalent O atoms. Both B–O bond lengths are 2.10 Å. There are ten inequivalent O sites. In the first O site, O is bonded to five Mg and one Ce atom to form OCeMg5 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, and edges with twelve OCeMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share corners with six OCeMg4B octahedra, corners with three equivalent OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 5–86°. In the third O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the fourth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–1°. In the fifth O site, O is bonded to five Mg and one Ce atom to form OCeMg5 octahedra that share corners with four OCeMg5 octahedra, corners with two equivalent OMg5 square pyramids, and edges with twelve OCeMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of O–Mg bond distances ranging from 2.02–2.26 Å. In the sixth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–1°. There are two shorter (2.14 Å) and two longer (2.17 Å) O–Mg bond lengths. In the seventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra, edges with ten OCeMg5 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–6°. In the eighth O site, O is bonded to four equivalent Mg, one Ce, and one B atom to form OCeMg4B octahedra that share corners with six OCeMg4B octahedra, corners with four equivalent OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the ninth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OCeMg4B octahedra, edges with ten OCeMg5 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–4°. In the tenth O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°.