DOI: 10.17188/1653003
title: Materials Data on KMg14Sb by Materials Project

description: KMg14Sb crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. K is bonded to twelve Mg atoms to form KMg12 cuboctahedra that share corners with six equivalent KMg12 cuboctahedra, corners with twelve equivalent MgMg10Sb2 cuboctahedra, edges with eighteen MgK2Mg10 cuboctahedra, faces with two equivalent SbMg12 cuboctahedra, and faces with eighteen MgK2Mg10 cuboctahedra. There are six shorter (3.26 Å) and six longer (3.36 Å) K–Mg bond lengths. There are five inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent K and ten Mg atoms to form distorted MgK2Mg10 cuboctahedra that share corners with four equivalent SbMg12 cuboctahedra, corners with fourteen MgK2Mg10 cuboctahedra, edges with two equivalent KMg12 cuboctahedra, edges with sixteen MgK2Mg10 cuboctahedra, faces with two equivalent KMg12 cuboctahedra, and faces with eighteen MgK2Mg10 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.20–3.32 Å. In the second Mg site, Mg is bonded to ten Mg and two equivalent Sb atoms to form distorted MgMg10Sb2 cuboctahedra that share corners with four equivalent KMg12 cuboctahedra, corners with fourteen MgK2Mg10 cuboctahedra, edges with two equivalent SbMg12 cuboctahedra, edges with sixteen MgMg10Sb2 cuboctahedra, faces with two equivalent SbMg12 cuboctahedra, and faces with eighteen MgK2Mg10 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.21–3.30 Å. Both Mg–Sb bond lengths are 3.26 Å. In the third Mg site, Mg is bonded to two equivalent K and ten Mg atoms to form distorted MgK2Mg10 cuboctahedra that share corners with four equivalent SbMg12 cuboctahedra, corners with fourteen MgMg10Sb2 cuboctahedra, edges with two equivalent KMg12 cuboctahedra, edges with sixteen MgK2Mg10 cuboctahedra, faces with two equivalent KMg12 cuboctahedra, and faces with eighteen MgK2Mg10 cuboctahedra. There are two shorter (3.25 Å) and four longer (3.31 Å) Mg–Mg bond lengths. In the fourth Mg site, Mg is bonded to one K, ten Mg, and one Sb atom to form distorted MgKMg10Sb cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with two equivalent KMg12 cuboctahedra, edges with two equivalent SbMg12 cuboctahedra, edges with fourteen MgK2Mg10 cuboctahedra, a faceface with one KMg12 cuboctahedra, a faceface with one SbMg12 cuboctahedra, and faces with eighteen MgK2Mg10 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.19–3.33 Å. The Mg–Sb bond length is 3.24 Å. In the fifth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with eighteen MgK2Mg10 cuboctahedra, faces with three equivalent KMg12 cuboctahedra, faces with three equivalent SbMg12 cuboctahedra, and faces with fourteen MgK2Mg10 cuboctahedra. Sb is bonded to twelve Mg atoms to form SbMg12 cuboctahedra that share corners with six equivalent SbMg12 cuboctahedra, corners with twelve MgK2Mg10 cuboctahedra, edges with eighteen MgMg10Sb2 cuboctahedra, faces with two equivalent KMg12 cuboctahedra, and faces with eighteen MgMg10Sb2 cuboctahedra.