DOI: 10.17188/1652700
title: Materials Data on HfMg6Sb by Materials Project

description: Mg6HfSb crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are seven inequivalent Mg sites. In the first Mg site, Mg is bonded to eight Mg, two equivalent Hf, and two equivalent Sb atoms to form distorted MgHf2Mg8Sb2 cuboctahedra that share corners with four equivalent SbHf2Mg10 cuboctahedra, corners with fourteen MgHf2Mg8Sb2 cuboctahedra, edges with two equivalent SbHf2Mg10 cuboctahedra, edges with four equivalent HfMg10Sb2 cuboctahedra, edges with twelve MgHf2Mg8Sb2 cuboctahedra, faces with two equivalent HfMg10Sb2 cuboctahedra, faces with two equivalent SbHf2Mg10 cuboctahedra, and faces with sixteen MgHf2Mg8Sb2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.11–3.26 Å. Both Mg–Hf bond lengths are 3.17 Å. There are one shorter (3.13 Å) and one longer (3.20 Å) Mg–Sb bond lengths. In the second Mg site, Mg is bonded to eight Mg, two equivalent Hf, and two equivalent Sb atoms to form distorted MgHf2Mg8Sb2 cuboctahedra that share corners with four equivalent SbHf2Mg10 cuboctahedra, corners with fourteen MgHf2Mg8Sb2 cuboctahedra, edges with two equivalent SbHf2Mg10 cuboctahedra, edges with four equivalent HfMg10Sb2 cuboctahedra, edges with twelve MgHf2Mg8Sb2 cuboctahedra, faces with two equivalent HfMg10Sb2 cuboctahedra, faces with two equivalent SbHf2Mg10 cuboctahedra, and faces with sixteen MgHf2Mg8Sb2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.11–3.26 Å. Both Mg–Hf bond lengths are 3.17 Å. There are one shorter (3.13 Å) and one longer (3.20 Å) Mg–Sb bond lengths. In the third Mg site, Mg is bonded to ten Mg and two equivalent Sb atoms to form distorted MgMg10Sb2 cuboctahedra that share corners with four equivalent SbHf2Mg10 cuboctahedra, corners with fourteen MgHf2Mg8Sb2 cuboctahedra, edges with two equivalent SbHf2Mg10 cuboctahedra, edges with sixteen MgHf2Mg8Sb2 cuboctahedra, faces with two equivalent SbHf2Mg10 cuboctahedra, faces with six equivalent HfMg10Sb2 cuboctahedra, and faces with twelve MgHf2Mg8Sb2 cuboctahedra. There are six shorter (3.14 Å) and one longer (3.16 Å) Mg–Mg bond lengths. Both Mg–Sb bond lengths are 3.24 Å. In the fourth Mg site, Mg is bonded to eight Mg, two equivalent Hf, and two equivalent Sb atoms to form distorted MgHf2Mg8Sb2 cuboctahedra that share corners with four equivalent HfMg10Sb2 cuboctahedra, corners with fourteen MgHf2Mg8Sb2 cuboctahedra, edges with two equivalent HfMg10Sb2 cuboctahedra, edges with four equivalent SbHf2Mg10 cuboctahedra, edges with twelve MgHf2Mg8Sb2 cuboctahedra, faces with two equivalent HfMg10Sb2 cuboctahedra, faces with two equivalent SbHf2Mg10 cuboctahedra, and faces with sixteen MgHf2Mg8Sb2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.14–3.31 Å. There are one shorter (3.14 Å) and one longer (3.18 Å) Mg–Hf bond lengths. Both Mg–Sb bond lengths are 3.20 Å. In the fifth Mg site, Mg is bonded to eight Mg, two equivalent Hf, and two equivalent Sb atoms to form distorted MgHf2Mg8Sb2 cuboctahedra that share corners with four equivalent HfMg10Sb2 cuboctahedra, corners with fourteen MgHf2Mg8Sb2 cuboctahedra, edges with two equivalent HfMg10Sb2 cuboctahedra, edges with four equivalent SbHf2Mg10 cuboctahedra, edges with twelve MgMg10Sb2 cuboctahedra, faces with two equivalent HfMg10Sb2 cuboctahedra, faces with two equivalent SbHf2Mg10 cuboctahedra, and faces with sixteen MgHf2Mg8Sb2 cuboctahedra. There are one shorter (3.14 Å) and one longer (3.18 Å) Mg–Mg bond lengths. There are one shorter (3.14 Å) and one longer (3.18 Å) Mg–Hf bond lengths. Both Mg–Sb bond lengths are 3.20 Å. In the sixth Mg site, Mg is bonded to ten Mg and two equivalent Hf atoms to form MgHf2Mg10 cuboctahedra that share corners with four equivalent HfMg10Sb2 cuboctahedra, corners with fourteen MgHf2Mg8Sb2 cuboctahedra, edges with two equivalent HfMg10Sb2 cuboctahedra, edges with sixteen MgHf2Mg8Sb2 cuboctahedra, faces with two equivalent HfMg10Sb2 cuboctahedra, faces with six equivalent SbHf2Mg10 cuboctahedra, and faces with twelve MgHf2Mg8Sb2 cuboctahedra. Both Mg–Hf bond lengths are 3.24 Å. In the seventh Mg site, Mg is bonded to eight Mg, two equivalent Hf, and two equivalent Sb atoms to form distorted MgHf2Mg8Sb2 cuboctahedra that share corners with four equivalent SbHf2Mg10 cuboctahedra, corners with fourteen MgHf2Mg8Sb2 cuboctahedra, edges with two equivalent SbHf2Mg10 cuboctahedra, edges with four equivalent HfMg10Sb2 cuboctahedra, edges with twelve MgHf2Mg8Sb2 cuboctahedra, faces with two equivalent HfMg10Sb2 cuboctahedra, faces with two equivalent SbHf2Mg10 cuboctahedra, and faces with sixteen MgHf2Mg8Sb2 cuboctahedra. There are two shorter (3.11 Å) and two longer (3.15 Å) Mg–Mg bond lengths. Both Mg–Hf bond lengths are 3.17 Å. There are one shorter (3.13 Å) and one longer (3.20 Å) Mg–Sb bond lengths. Hf is bonded to ten Mg and two equivalent Sb atoms to form distorted HfMg10Sb2 cuboctahedra that share corners with six equivalent HfMg10Sb2 cuboctahedra, corners with twelve MgHf2Mg8Sb2 cuboctahedra, edges with four equivalent SbHf2Mg10 cuboctahedra, edges with fourteen MgHf2Mg8Sb2 cuboctahedra, faces with two equivalent HfMg10Sb2 cuboctahedra, faces with two equivalent SbHf2Mg10 cuboctahedra, and faces with sixteen MgHf2Mg8Sb2 cuboctahedra. Both Hf–Sb bond lengths are 3.08 Å. Sb is bonded to ten Mg and two equivalent Hf atoms to form SbHf2Mg10 cuboctahedra that share corners with six equivalent SbHf2Mg10 cuboctahedra, corners with twelve MgHf2Mg8Sb2 cuboctahedra, edges with four equivalent HfMg10Sb2 cuboctahedra, edges with fourteen MgHf2Mg8Sb2 cuboctahedra, faces with two equivalent HfMg10Sb2 cuboctahedra, faces with two equivalent SbHf2Mg10 cuboctahedra, and faces with sixteen MgHf2Mg8Sb2 cuboctahedra.