DOI: 10.17188/1674273
title: Materials Data on NaMg14Si by Materials Project

description: NaMg14Si crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Na is bonded to ten Mg and two equivalent Si atoms to form NaMg10Si2 cuboctahedra that share corners with six equivalent NaMg10Si2 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent SiNa2Mg10 cuboctahedra, edges with sixteen MgNaMg10Si cuboctahedra, faces with two equivalent SiNa2Mg10 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra. There are a spread of Na–Mg bond distances ranging from 3.15–3.23 Å. Both Na–Si bond lengths are 3.17 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 NaMg10Si2 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with eighteen MgNaMg10Si cuboctahedra, faces with two equivalent SiNa2Mg10 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.16–3.21 Å. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent SiNa2Mg10 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with eighteen MgNaMg10Si cuboctahedra, faces with two equivalent NaMg10Si2 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.16–3.21 Å. In the third Mg site, Mg is bonded to two equivalent Na, eight Mg, and two equivalent Si atoms to form distorted MgNa2Mg8Si2 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with two equivalent NaMg10Si2 cuboctahedra, edges with two equivalent SiNa2Mg10 cuboctahedra, edges with fourteen MgNa2Mg8Si2 cuboctahedra, faces with two equivalent NaMg10Si2 cuboctahedra, faces with two equivalent SiNa2Mg10 cuboctahedra, and faces with sixteen MgNa2Mg8Si2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.15–3.21 Å. There are one shorter (3.14 Å) and one longer (3.18 Å) Mg–Si bond lengths. In the fourth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent NaMg10Si2 cuboctahedra, corners with four equivalent SiNa2Mg10 cuboctahedra, corners with ten MgNa2Mg8Si2 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, and faces with twenty MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.15–3.22 Å. In the fifth Mg site, Mg is bonded to one Na, ten Mg, and one Si atom to form distorted MgNaMg10Si cuboctahedra that share corners with eighteen MgNaMg10Si cuboctahedra, edges with two equivalent NaMg10Si2 cuboctahedra, edges with two equivalent SiNa2Mg10 cuboctahedra, edges with fourteen MgMg12 cuboctahedra, a faceface with one NaMg10Si2 cuboctahedra, a faceface with one SiNa2Mg10 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.13–3.21 Å. The Mg–Si bond length is 3.16 Å. In the sixth Mg site, Mg is bonded to eleven Mg and one Si atom to form distorted MgMg11Si cuboctahedra that share corners with eighteen MgNaMg10Si cuboctahedra, edges with two equivalent SiNa2Mg10 cuboctahedra, edges with sixteen MgMg12 cuboctahedra, a faceface with one SiNa2Mg10 cuboctahedra, faces with three equivalent NaMg10Si2 cuboctahedra, and faces with sixteen MgMg12 cuboctahedra. Both Mg–Mg bond lengths are 3.17 Å. The Mg–Si bond length is 3.16 Å. In the seventh Mg site, Mg is bonded to one Na and eleven Mg atoms to form distorted MgNaMg11 cuboctahedra that share corners with eighteen MgNaMg10Si cuboctahedra, edges with two equivalent NaMg10Si2 cuboctahedra, edges with sixteen MgMg12 cuboctahedra, a faceface with one NaMg10Si2 cuboctahedra, faces with three equivalent SiNa2Mg10 cuboctahedra, and faces with sixteen MgMg12 cuboctahedra. Si is bonded to two equivalent Na and ten Mg atoms to form SiNa2Mg10 cuboctahedra that share corners with six equivalent SiNa2Mg10 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent NaMg10Si2 cuboctahedra, edges with sixteen MgNaMg10Si cuboctahedra, faces with two equivalent NaMg10Si2 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra.