DOI: 10.17188/1654657
title: Materials Data on CaYMg6O8 by Materials Project

description: CaMg6YO8 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Ca is bonded to six O atoms to form CaO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four equivalent CaO6 octahedra, edges with four equivalent YO6 octahedra, and edges with eight equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.26 Å) and two longer (2.38 Å) Ca–O bond lengths. There are three 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 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 (2.07 Å) and four longer (2.26 Å) Mg–O bond lengths. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent YO6 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 (2.12 Å) and four longer (2.26 Å) Mg–O bond lengths. In the third Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six equivalent MgO6 octahedra, edges with two equivalent CaO6 octahedra, edges with two equivalent YO6 octahedra, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Mg–O bond distances ranging from 2.06–2.39 Å. Y is bonded to six O atoms to form YO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four equivalent YO6 octahedra, edges with four equivalent CaO6 octahedra, and edges with eight equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.26 Å) and two longer (2.33 Å) Y–O bond lengths. There are five inequivalent O sites. In the first O site, O is bonded to one Ca and five Mg atoms to form OCaMg5 octahedra that share corners with six equivalent OCaMg5 octahedra and edges with twelve OYMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second O site, O is bonded to five Mg and one Y atom to form OYMg5 octahedra that share corners with six equivalent OYMg5 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the third O site, O is bonded to two equivalent Ca, two equivalent Mg, and two equivalent Y atoms to form OCa2Y2Mg2 octahedra that share corners with six OCa2Y2Mg2 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OCa2Y2Mg2 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OCa2Y2Mg2 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. Both O–Mg bond lengths are 2.06 Å.