DOI: 10.17188/1719227
title: Materials Data on NaCaMg6 by Materials Project

description: NaCaMg6 is beta Cu3Ti-derived structured and crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Na is bonded to two equivalent Ca and ten Mg atoms to form NaCa2Mg10 cuboctahedra that share corners with six equivalent NaCa2Mg10 cuboctahedra, corners with twelve MgNa2Mg10 cuboctahedra, edges with four equivalent CaNa2Mg10 cuboctahedra, edges with fourteen MgNa2Mg10 cuboctahedra, faces with two equivalent NaCa2Mg10 cuboctahedra, faces with two equivalent CaNa2Mg10 cuboctahedra, and faces with sixteen MgNa2Ca2Mg8 cuboctahedra. Both Na–Ca bond lengths are 3.35 Å. There are a spread of Na–Mg bond distances ranging from 3.31–3.36 Å. Ca is bonded to two equivalent Na and ten Mg atoms to form CaNa2Mg10 cuboctahedra that share corners with six equivalent CaNa2Mg10 cuboctahedra, corners with twelve MgNa2Ca2Mg8 cuboctahedra, edges with four equivalent NaCa2Mg10 cuboctahedra, edges with fourteen MgNa2Ca2Mg8 cuboctahedra, faces with two equivalent NaCa2Mg10 cuboctahedra, faces with two equivalent CaNa2Mg10 cuboctahedra, and faces with sixteen MgNa2Ca2Mg8 cuboctahedra. There are a spread of Ca–Mg bond distances ranging from 3.32–3.35 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent Na, two equivalent Ca, and eight Mg atoms to form distorted MgNa2Ca2Mg8 cuboctahedra that share corners with four equivalent CaNa2Mg10 cuboctahedra, corners with fourteen MgNa2Ca2Mg8 cuboctahedra, edges with two equivalent CaNa2Mg10 cuboctahedra, edges with four equivalent NaCa2Mg10 cuboctahedra, edges with twelve MgNa2Ca2Mg8 cuboctahedra, faces with two equivalent NaCa2Mg10 cuboctahedra, faces with two equivalent CaNa2Mg10 cuboctahedra, and faces with sixteen MgNa2Ca2Mg8 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.30–3.36 Å. In the second Mg site, Mg is bonded to two equivalent Ca and ten Mg atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with four equivalent CaNa2Mg10 cuboctahedra, corners with fourteen MgNa2Ca2Mg8 cuboctahedra, edges with two equivalent CaNa2Mg10 cuboctahedra, edges with sixteen MgNa2Mg10 cuboctahedra, faces with two equivalent CaNa2Mg10 cuboctahedra, faces with six equivalent NaCa2Mg10 cuboctahedra, and faces with twelve MgNa2Ca2Mg8 cuboctahedra. There are four shorter (3.32 Å) and two longer (3.34 Å) Mg–Mg bond lengths. In the third Mg site, Mg is bonded to two equivalent Na, two equivalent Ca, and eight Mg atoms to form distorted MgNa2Ca2Mg8 cuboctahedra that share corners with four equivalent NaCa2Mg10 cuboctahedra, corners with fourteen MgNa2Mg10 cuboctahedra, edges with two equivalent NaCa2Mg10 cuboctahedra, edges with four equivalent CaNa2Mg10 cuboctahedra, edges with twelve MgNa2Ca2Mg8 cuboctahedra, faces with two equivalent NaCa2Mg10 cuboctahedra, faces with two equivalent CaNa2Mg10 cuboctahedra, and faces with sixteen MgNa2Ca2Mg8 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.31–3.34 Å. In the fourth Mg site, Mg is bonded to two equivalent Na and ten Mg atoms to form distorted MgNa2Mg10 cuboctahedra that share corners with four equivalent NaCa2Mg10 cuboctahedra, corners with fourteen MgNa2Mg10 cuboctahedra, edges with two equivalent NaCa2Mg10 cuboctahedra, edges with sixteen MgNa2Ca2Mg8 cuboctahedra, faces with two equivalent NaCa2Mg10 cuboctahedra, faces with six equivalent CaNa2Mg10 cuboctahedra, and faces with twelve MgNa2Ca2Mg8 cuboctahedra.