Materials Data on Mg2ZnSb2 by Materials Project
Mg2ZnSb2 crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four Sb3- atoms to form MgSb4 tetrahedra that share corners with six equivalent MgSb6 octahedra, corners with six equivalent MgSb4 tetrahedra, edges with three equivalent MgSb6 octahedra, and edges with three equivalent ZnSb4 tetrahedra. The corner-sharing octahedra tilt angles range from 9–56°. There are three shorter (2.81 Å) and one longer (2.86 Å) Mg–Sb bond lengths. In the second Mg2+ site, Mg2+ is bonded to six Sb3- atoms to form MgSb6 octahedra that share corners with six equivalent MgSb4 tetrahedra, corners with six equivalent ZnSb4 tetrahedra, edges with six equivalent MgSb6 octahedra, edges with three equivalent MgSb4 tetrahedra, and edges with three equivalent ZnSb4 tetrahedra. There are three shorter (3.04 Å) and three longer (3.12 Å) Mg–Sb bond lengths. Zn2+ is bonded to four Sb3- atoms to form ZnSb4 tetrahedra that share corners with six equivalent MgSb6 octahedra, corners with six equivalent ZnSb4 tetrahedra, edges with three equivalent MgSb6 octahedra, and edges with three equivalent MgSb4 tetrahedra. The corner-sharing octahedra tilt angles range from 12–59°. There are three shorter (2.79 Å) and one longer (2.91 Å) Zn–Sb bond lengths. There are two inequivalent Sb3- sites. In the first Sb3- site, Sb3- is bonded in a 7-coordinate geometry to six Mg2+ and one Zn2+ atom. In the second Sb3- site, Sb3- is bonded to four Mg2+ and three equivalent Zn2+ atoms to form distorted edge-sharing SbMg4Zn3 pentagonal bipyramids.