Materials Data on MgZn2 by Materials Project

Abstract

MgZn2 crystallizes in the trigonal R32 space group. The structure is three-dimensional. Mg is bonded to three equivalent Mg and nine Zn atoms to form MgMg3Zn9 cuboctahedra that share corners with twelve equivalent MgMg3Zn9 cuboctahedra, edges with six equivalent MgMg3Zn9 cuboctahedra, edges with twelve ZnMg4Zn8 cuboctahedra, faces with four equivalent MgMg3Zn9 cuboctahedra, and faces with twelve ZnMg4Zn8 cuboctahedra. All Mg–Mg bond lengths are 2.81 Å. There are a spread of Mg–Zn bond distances ranging from 2.81–3.03 Å. There are four inequivalent Zn sites. In the first Zn site, Zn is bonded to four equivalent Mg and eight Zn atoms to form distorted ZnMg4Zn8 cuboctahedra that share corners with eighteen ZnMg4Zn8 cuboctahedra, edges with six equivalent ZnMg4Zn8 cuboctahedra, edges with eight equivalent MgMg3Zn9 cuboctahedra, faces with eight equivalent MgMg3Zn9 cuboctahedra, and faces with eight equivalent ZnMg4Zn8 cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.79–3.01 Å. In the second Zn site, Zn is bonded to four equivalent Mg and eight Zn atoms to form distorted ZnMg4Zn8 cuboctahedra that share corners with eighteen ZnMg4Zn8 cuboctahedra, edges with six equivalent ZnMg4Zn8 cuboctahedra, edges with eight equivalent MgMg3Zn9 cuboctahedra, faces with eight equivalent MgMg3Zn9 cuboctahedra, and faces with eight ZnMg4Zn8 cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.79–3.01 Å. In the third Zn site, Zn is bonded in a distorted hexagonal planar geometry to six equivalent Mg and six Zn atoms. In the fourth Zn site, Zn is bonded to four equivalent Mg and eight Zn atoms to form distorted ZnMg4Zn8 cuboctahedra that share corners with eighteen ZnMg4Zn8 cuboctahedra, edges with six equivalent ZnMg4Zn8 cuboctahedra, edges with eight equivalent MgMg3Zn9 cuboctahedra, faces with eight equivalent MgMg3Zn9 cuboctahedra, and faces with eight equivalent ZnMg4Zn8 cuboctahedra. There are two shorter (3.01 Å) and two longer (3.03 Å) Zn–Mg bond lengths. There are a spread of Zn–Zn bond distances ranging from 2.79–3.01 Å.