DOI: 10.17188/1741939
title: Materials Data on CsMg6AlO8 by Materials Project

description: CsMg6AlO8 is Caswellsilverite-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Cs1+ is bonded to six O2- atoms to form CsO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four equivalent CsO6 octahedra, edges with four equivalent AlO6 octahedra, and edges with eight equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.33 Å) and two longer (2.55 Å) Cs–O bond lengths. There are three 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 AlO6 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 (2.33 Å) and two longer (2.46 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 two equivalent CsO6 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 (1.88 Å) and four longer (2.33 Å) Mg–O bond lengths. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent MgO6 octahedra, edges with two equivalent CsO6 octahedra, edges with two equivalent AlO6 octahedra, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–16°. There are a spread of Mg–O bond distances ranging from 2.14–2.36 Å. Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four equivalent AlO6 octahedra, edges with four equivalent CsO6 octahedra, and edges with eight equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (1.97 Å) and four longer (2.33 Å) Al–O bond lengths. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded to five Mg2+ and one Al3+ atom to form distorted OMg5Al octahedra that share corners with six equivalent OMg5Al octahedra and edges with twelve OCsMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–16°. In the second O2- site, O2- is bonded to one Cs1+ and five Mg2+ atoms to form distorted OCsMg5 octahedra that share corners with six equivalent OCsMg5 octahedra and edges with twelve OMg5Al octahedra. The corner-sharing octahedra tilt angles range from 0–13°. In the third O2- site, O2- is bonded to two equivalent Cs1+, two equivalent Mg2+, and two equivalent Al3+ atoms to form OCs2Mg2Al2 octahedra that share corners with six OCs2Mg2Al2 octahedra and edges with twelve OMg5Al octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OCs2Mg2Al2 octahedra and edges with twelve OMg5Al octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifth O2- site, O2- is bonded to two equivalent Cs1+, two equivalent Mg2+, and two equivalent Al3+ atoms to form OCs2Mg2Al2 octahedra that share corners with six OCs2Mg2Al2 octahedra and edges with twelve OMg5Al octahedra. The corner-sharing octahedral tilt angles are 0°. Both O–Mg bond lengths are 2.29 Å. In the sixth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OCs2Mg2Al2 octahedra and edges with twelve OMg5Al octahedra. The corner-sharing octahedral tilt angles are 0°. Both O–Mg bond lengths are 2.14 Å.