DOI: 10.17188/1751365
title: Materials Data on YHfMg14O16 by Materials Project

description: Mg14YHfO16 is alpha Po-derived structured and crystallizes in the orthorhombic Pmmm 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 YO6 octahedra, corners with four MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.09 Å) and four longer (2.20 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 HfO6 octahedra, corners with four MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.10 Å) and four longer (2.20 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 MgO6 octahedra, edges with two equivalent YO6 octahedra, edges with two equivalent HfO6 octahedra, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.15–2.24 Å. In the fourth Mg site, Mg is bonded to six O atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.18–2.21 Å. In the fifth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent YO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Mg–O bond distances ranging from 2.07–2.31 Å. In the sixth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent HfO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Mg–O bond distances ranging from 2.12–2.27 Å. In the seventh Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent HfO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Mg–O bond distances ranging from 2.12–2.27 Å. In the eighth 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 YO6 octahedra, an edgeedge with one HfO6 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 2.10–2.29 Å. Y is bonded to six O atoms to form YO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent YO6 octahedra, corners with two equivalent HfO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Y–O bond distances ranging from 2.20–2.30 Å. Hf is bonded to six O atoms to form HfO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent YO6 octahedra, corners with two equivalent HfO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Hf–O bond distances ranging from 2.16–2.28 Å. There are nine inequivalent O sites. In the first O site, O is bonded to five Mg and one Y atom to form OYMg5 octahedra that share corners with six OYMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second O site, O is bonded to five Mg and one Hf atom to form OHfMg5 octahedra that share corners with six OYMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the third 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 OYMg5 octahedra. The corner-sharing octahedra tilt angles range from 1–5°. In the fourth O site, O is bonded to four Mg and two equivalent Y atoms to form OY2Mg4 octahedra that share corners with six OY2Mg4 octahedra and edges with twelve OYMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifth O site, O is bonded to four Mg and two equivalent Hf atoms to form OHf2Mg4 octahedra that share corners with six OY2Mg4 octahedra and edges with twelve OHfMg5 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 OY2Mg4 octahedra and edges with twelve OYMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the seventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OHf2Mg4 octahedra and edges with twelve OHfMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the eighth O site, O is bonded to four Mg, one Y, and one Hf atom to form OYHfMg4 octahedra that share corners with six OYHfMg4 octahedra and edges with twelve OYMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the ninth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OYHfMg4 octahedra and edges with twelve OYMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°.