DOI: 10.17188/1672524
title: Materials Data on CsMg14SiO16 by Materials Project

description: CsMg14SiO16 is Caswellsilverite-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Cs is bonded to six O atoms to form CsO6 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 (2.23 Å) and four longer (2.52 Å) Cs–O bond lengths. There are five 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 CsO6 octahedra, corners with two equivalent MgO6 octahedra, corners with two equivalent SiO6 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 1.87–2.32 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent SiO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. There are a spread of Mg–O bond distances ranging from 2.19–2.24 Å. In the third Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent CsO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–11°. There are a spread of Mg–O bond distances ranging from 2.09–2.30 Å. In the fourth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent CsO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–11°. There are a spread of Mg–O bond distances ranging from 2.09–2.30 Å. In the fifth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six equivalent MgO6 octahedra, an edgeedge with one CsO6 octahedra, an edgeedge with one SiO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–16°. There are a spread of Mg–O bond distances ranging from 2.18–2.24 Å. Si is bonded to six O atoms to form SiO6 octahedra that share corners with two equivalent SiO6 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 (2.07 Å) and two longer (2.23 Å) Si–O bond lengths. There are nine inequivalent O sites. In the first O site, O is bonded to five Mg and one Si atom to form a mixture of edge and corner-sharing OMg5Si octahedra. The corner-sharing octahedra tilt angles range from 0–11°. In the second O site, O is bonded to one Cs and five Mg atoms to form a mixture of distorted edge and corner-sharing OCsMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–11°. Both O–Mg bond lengths are 2.24 Å. In the third O site, O is bonded to one Cs and five Mg atoms to form a mixture of distorted edge and corner-sharing OCsMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–11°. All O–Mg bond lengths are 2.24 Å. In the fourth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OMg5Si octahedra. The corner-sharing octahedra tilt angles range from 1–5°. In the fifth O site, O is bonded to four equivalent Mg and two equivalent Si atoms to form OMg4Si2 octahedra that share corners with six OMg4Si2 octahedra and edges with twelve OMg5Si octahedra. The corner-sharing octahedral tilt angles are 0°. In the sixth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg4Si2 octahedra and edges with twelve OMg5Si octahedra. The corner-sharing octahedral tilt angles are 0°. In the seventh O site, O is bonded to two equivalent Cs and four Mg atoms to form OCs2Mg4 octahedra that share corners with six OMg6 octahedra and edges with twelve OCsMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the eighth O site, O is bonded to one Cs and five Mg atoms to form a mixture of distorted edge and corner-sharing OCsMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–11°. The O–Mg bond length is 1.87 Å. In the ninth O site, O is bonded to one Cs and five Mg atoms to form a mixture of distorted edge and corner-sharing OCsMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–11°. There are one shorter (1.87 Å) and two longer (2.24 Å) O–Mg bond lengths.