Materials Data on CsHfMg6 by Materials Project

Abstract

CsMg6Hf crystallizes in the monoclinic Pm space group. The structure is three-dimensional. Cs is bonded to twelve Mg atoms to form CsMg12 cuboctahedra that share corners with four equivalent CsMg12 cuboctahedra, corners with eight equivalent HfMg12 cuboctahedra, edges with eight MgCs2Hf2Mg8 cuboctahedra, faces with two equivalent CsMg12 cuboctahedra, faces with four MgCs2Hf2Mg8 cuboctahedra, and faces with four equivalent HfMg12 cuboctahedra. There are a spread of Cs–Mg bond distances ranging from 3.48–3.69 Å. There are six inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent Cs, eight Mg, and two equivalent Hf atoms to form distorted MgCs2Hf2Mg8 cuboctahedra that share corners with twelve MgCs2Hf2Mg8 cuboctahedra, edges with four equivalent CsMg12 cuboctahedra, edges with four equivalent HfMg12 cuboctahedra, faces with two equivalent CsMg12 cuboctahedra, faces with two equivalent HfMg12 cuboctahedra, and faces with six MgCs2Hf2Mg8 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.36–3.42 Å. There are one shorter (3.45 Å) and one longer (3.51 Å) Mg–Hf bond lengths. In the second Mg site, Mg is bonded to two equivalent Cs, eight Mg, and two equivalent Hf atoms to form distorted MgCs2Hf2Mg8 cuboctahedra that share corners with twelve MgCs2Hf2Mg8 cuboctahedra, edges with four equivalent CsMg12 cuboctahedra, edges with four equivalent HfMg12 cuboctahedra, faces with two equivalent CsMg12 cuboctahedra, faces with two equivalent HfMg12 cuboctahedra, and faces with six MgCs2Hf2Mg8 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.37–3.42 Å. There are one shorter (3.45 Å) and one longer (3.51 Å) Mg–Hf bond lengths. In the third Mg site, Mg is bonded in a 10-coordinate geometry to two equivalent Cs, six Mg, and two equivalent Hf atoms. There are one shorter (2.93 Å) and one longer (2.97 Å) Mg–Mg bond lengths. Both Mg–Hf bond lengths are 3.12 Å. In the fourth Mg site, Mg is bonded in a 10-coordinate geometry to two equivalent Cs, six Mg, and two equivalent Hf atoms. There are one shorter (2.94 Å) and one longer (2.96 Å) Mg–Mg bond lengths. Both Mg–Hf bond lengths are 3.11 Å. In the fifth Mg site, Mg is bonded in a 10-coordinate geometry to two equivalent Cs, six Mg, and two equivalent Hf atoms. Both Mg–Hf bond lengths are 3.11 Å. In the sixth Mg site, Mg is bonded in a 10-coordinate geometry to two equivalent Cs, six Mg, and two equivalent Hf atoms. Both Mg–Hf bond lengths are 3.12 Å. Hf is bonded to twelve Mg atoms to form HfMg12 cuboctahedra that share corners with four equivalent HfMg12 cuboctahedra, corners with eight equivalent CsMg12 cuboctahedra, edges with eight MgCs2Hf2Mg8 cuboctahedra, faces with two equivalent HfMg12 cuboctahedra, faces with four equivalent CsMg12 cuboctahedra, and faces with four MgCs2Hf2Mg8 cuboctahedra.