Materials Data on Mg2Bi by Materials Project

Abstract

BiMg2 crystallizes in the trigonal R32 space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent Mg and four equivalent Bi atoms to form distorted MgMg2Bi4 cuboctahedra that share corners with twelve equivalent BiMg9 cuboctahedra, corners with sixteen MgMg2Bi4 cuboctahedra, edges with ten MgMg2Bi4 cuboctahedra, and faces with two equivalent MgMg2Bi4 cuboctahedra. Both Mg–Mg bond lengths are 3.30 Å. There are two shorter (3.28 Å) and two longer (3.33 Å) Mg–Bi bond lengths. In the second Mg site, Mg is bonded to six equivalent Mg and six equivalent Bi atoms to form distorted MgMg6Bi6 cuboctahedra that share corners with six equivalent BiMg9 cuboctahedra, corners with eighteen MgMg2Bi4 cuboctahedra, edges with six equivalent BiMg9 cuboctahedra, edges with eighteen MgMg2Bi4 cuboctahedra, and faces with two equivalent BiMg9 cuboctahedra. All Mg–Bi bond lengths are 3.35 Å. Bi is bonded to nine Mg atoms to form distorted BiMg9 cuboctahedra that share corners with eighteen equivalent BiMg9 cuboctahedra, corners with twenty-one MgMg2Bi4 cuboctahedra, edges with three equivalent MgMg6Bi6 cuboctahedra, a faceface with one MgMg6Bi6 cuboctahedra, and faces with four equivalent BiMg9 cuboctahedra.