DOI: 10.17188/1696383
title: Materials Data on RbCeMg14O16 by Materials Project

description: RbMg14CeO16 is Caswellsilverite-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Rb1+ is bonded to six O2- atoms to form RbO6 octahedra that share corners with two equivalent RbO6 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 (2.28 Å) and four longer (2.46 Å) Rb–O bond lengths. There are four 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 RbO6 octahedra, corners with two equivalent MgO6 octahedra, corners with two equivalent CeO6 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 1.95–2.28 Å. 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 CeO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of Mg–O bond distances ranging from 2.05–2.35 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 RbO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. There are a spread of Mg–O bond distances ranging from 2.19–2.29 Å. In the fourth 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 RbO6 octahedra, an edgeedge with one CeO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–17°. There are a spread of Mg–O bond distances ranging from 2.16–2.28 Å. Ce3+ is bonded to six O2- atoms to form CeO6 octahedra that share corners with two equivalent CeO6 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 (2.28 Å) and four longer (2.30 Å) Ce–O bond lengths. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded to five Mg2+ and one Ce3+ atom to form a mixture of corner and edge-sharing OCeMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. In the second O2- site, O2- is bonded to one Rb1+ and five Mg2+ atoms to form a mixture of distorted corner and edge-sharing ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. Both O–Mg bond lengths are 2.29 Å. In the third O2- site, O2- is bonded to one Rb1+ and five Mg2+ atoms to form a mixture of distorted corner and edge-sharing ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. There are two shorter (2.16 Å) and two longer (2.29 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 OCeMg5 octahedra. The corner-sharing octahedra tilt angles range from 1–9°. In the fifth O2- site, O2- is bonded to four equivalent Mg2+ and two equivalent Ce3+ atoms to form OCe2Mg4 octahedra that share corners with six OCe2Mg4 octahedra and edges with twelve OCeMg5 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 OCe2Mg4 octahedra and edges with twelve OCeMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the seventh O2- site, O2- is bonded to two equivalent Rb1+ and four equivalent Mg2+ atoms to form ORb2Mg4 octahedra that share corners with six OMg6 octahedra and edges with twelve ORbMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the eighth O2- site, O2- is bonded to five Mg2+ and one Ce3+ atom to form a mixture of corner and edge-sharing OCeMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. There are two shorter (2.27 Å) and two longer (2.28 Å) O–Mg bond lengths. In the ninth O2- site, O2- is bonded to one Rb1+ and five Mg2+ atoms to form a mixture of distorted corner and edge-sharing ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. The O–Mg bond length is 1.95 Å. In the tenth O2- site, O2- is bonded to one Rb1+ and five Mg2+ atoms to form a mixture of distorted corner and edge-sharing ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. There are a spread of O–Mg bond distances ranging from 1.95–2.29 Å.