DOI: 10.17188/1672006
title: Materials Data on RbHfMg14 by Materials Project

description: RbMg14Hf crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Rb is bonded to ten Mg and two equivalent Hf atoms to form RbHf2Mg10 cuboctahedra that share corners with six equivalent RbHf2Mg10 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent HfRb2Mg10 cuboctahedra, edges with eight MgRb2Hf2Mg8 cuboctahedra, faces with two equivalent HfRb2Mg10 cuboctahedra, and faces with fourteen MgMg12 cuboctahedra. There are a spread of Rb–Mg bond distances ranging from 3.28–3.38 Å. Both Rb–Hf bond lengths are 3.35 Å. There are seven inequivalent Mg sites. In the first Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent HfRb2Mg10 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with ten MgMg12 cuboctahedra, faces with two equivalent RbHf2Mg10 cuboctahedra, and faces with fourteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.16–3.34 Å. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent RbHf2Mg10 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with ten MgHfMg11 cuboctahedra, faces with two equivalent HfRb2Mg10 cuboctahedra, and faces with fourteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.12–3.31 Å. In the third Mg site, Mg is bonded to two equivalent Rb, eight Mg, and two equivalent Hf atoms to form distorted MgRb2Hf2Mg8 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with two equivalent RbHf2Mg10 cuboctahedra, edges with two equivalent HfRb2Mg10 cuboctahedra, edges with ten MgRb2Hf2Mg8 cuboctahedra, faces with two equivalent RbHf2Mg10 cuboctahedra, faces with two equivalent HfRb2Mg10 cuboctahedra, and faces with eight MgRb2Hf2Mg8 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.20–3.36 Å. There are one shorter (3.16 Å) and one longer (3.40 Å) Mg–Hf bond lengths. In the fourth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent RbHf2Mg10 cuboctahedra, corners with four equivalent HfRb2Mg10 cuboctahedra, corners with ten MgRb2Hf2Mg8 cuboctahedra, edges with fourteen MgMg12 cuboctahedra, and faces with twelve MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.10–3.39 Å. In the fifth Mg site, Mg is bonded in a 1-coordinate geometry to one Rb, eight Mg, and one Hf atom. There are a spread of Mg–Mg bond distances ranging from 3.15–3.42 Å. The Mg–Hf bond length is 3.23 Å. In the sixth Mg site, Mg is bonded to one Rb and eleven Mg atoms to form distorted MgRbMg11 cuboctahedra that share corners with ten MgHfMg11 cuboctahedra, edges with two equivalent RbHf2Mg10 cuboctahedra, edges with twelve MgMg12 cuboctahedra, a faceface with one RbHf2Mg10 cuboctahedra, faces with three equivalent HfRb2Mg10 cuboctahedra, and faces with twelve MgMg12 cuboctahedra. Both Mg–Mg bond lengths are 3.35 Å. In the seventh Mg site, Mg is bonded to eleven Mg and one Hf atom to form MgHfMg11 cuboctahedra that share corners with ten MgHfMg11 cuboctahedra, edges with two equivalent HfRb2Mg10 cuboctahedra, edges with twelve MgMg12 cuboctahedra, a faceface with one HfRb2Mg10 cuboctahedra, faces with three equivalent RbHf2Mg10 cuboctahedra, and faces with twelve MgMg12 cuboctahedra. The Mg–Hf bond length is 3.23 Å. Hf is bonded to two equivalent Rb and ten Mg atoms to form distorted HfRb2Mg10 cuboctahedra that share corners with six equivalent HfRb2Mg10 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent RbHf2Mg10 cuboctahedra, edges with eight MgHfMg11 cuboctahedra, faces with two equivalent RbHf2Mg10 cuboctahedra, and faces with fourteen MgMg12 cuboctahedra.