Materials Data on NaMg6Nb by Materials Project

Abstract

NaMg6Nb is beta Cu3Ti-derived structured and crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Na is bonded to twelve Mg atoms to form NaMg12 cuboctahedra that share corners with four equivalent NaMg12 cuboctahedra, corners with eight equivalent NbMg12 cuboctahedra, edges with twenty-four MgNa2Mg8Nb2 cuboctahedra, faces with two equivalent NaMg12 cuboctahedra, faces with four equivalent NbMg12 cuboctahedra, and faces with twelve MgNa2Mg8Nb2 cuboctahedra. There are a spread of Na–Mg bond distances ranging from 3.14–3.32 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent Na, eight Mg, and two equivalent Nb atoms to form distorted MgNa2Mg8Nb2 cuboctahedra that share corners with twelve equivalent MgNa2Mg8Nb2 cuboctahedra, edges with four equivalent NaMg12 cuboctahedra, edges with four equivalent NbMg12 cuboctahedra, edges with sixteen MgNa2Mg8Nb2 cuboctahedra, faces with two equivalent NaMg12 cuboctahedra, faces with two equivalent NbMg12 cuboctahedra, and faces with fourteen MgNa2Mg8Nb2 cuboctahedra. There are four shorter (3.16 Å) and four longer (3.19 Å) Mg–Mg bond lengths. Both Mg–Nb bond lengths are 3.14 Å. In the second Mg site, Mg is bonded to two equivalent Na, eight Mg, and two equivalent Nb atoms to form distorted MgNa2Mg8Nb2 cuboctahedra that share corners with twelve equivalent MgNa2Mg8Nb2 cuboctahedra, edges with four equivalent NaMg12 cuboctahedra, edges with four equivalent NbMg12 cuboctahedra, edges with sixteen MgNa2Mg8Nb2 cuboctahedra, faces with two equivalent NaMg12 cuboctahedra, faces with two equivalent NbMg12 cuboctahedra, and faces with fourteen MgNa2Mg8Nb2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.93–3.36 Å. Both Mg–Nb bond lengths are 3.08 Å. In the third Mg site, Mg is bonded to two equivalent Na, eight Mg, and two equivalent Nb atoms to form distorted MgNa2Mg8Nb2 cuboctahedra that share corners with twelve MgNa2Mg8Nb2 cuboctahedra, edges with four equivalent NaMg12 cuboctahedra, edges with four equivalent NbMg12 cuboctahedra, edges with sixteen MgNa2Mg8Nb2 cuboctahedra, faces with two equivalent NaMg12 cuboctahedra, faces with two equivalent NbMg12 cuboctahedra, and faces with fourteen MgNa2Mg8Nb2 cuboctahedra. Both Mg–Nb bond lengths are 3.06 Å. In the fourth Mg site, Mg is bonded to two equivalent Na, eight Mg, and two equivalent Nb atoms to form distorted MgNa2Mg8Nb2 cuboctahedra that share corners with twelve MgNa2Mg8Nb2 cuboctahedra, edges with four equivalent NaMg12 cuboctahedra, edges with four equivalent NbMg12 cuboctahedra, edges with sixteen MgNa2Mg8Nb2 cuboctahedra, faces with two equivalent NaMg12 cuboctahedra, faces with two equivalent NbMg12 cuboctahedra, and faces with fourteen MgNa2Mg8Nb2 cuboctahedra. Both Mg–Nb bond lengths are 3.07 Å. Nb is bonded to twelve Mg atoms to form NbMg12 cuboctahedra that share corners with four equivalent NbMg12 cuboctahedra, corners with eight equivalent NaMg12 cuboctahedra, edges with twenty-four MgNa2Mg8Nb2 cuboctahedra, faces with two equivalent NbMg12 cuboctahedra, faces with four equivalent NaMg12 cuboctahedra, and faces with twelve MgNa2Mg8Nb2 cuboctahedra.