Materials Data on Li2MgBr4 by Materials Project

Abstract

Li2MgBr4 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six Br1- atoms to form LiBr6 octahedra that share corners with six equivalent MgBr6 octahedra, edges with two equivalent MgBr6 octahedra, and edges with six LiBr6 octahedra. The corner-sharing octahedra tilt angles range from 2–5°. There are two shorter (2.70 Å) and four longer (2.86 Å) Li–Br bond lengths. In the second Li1+ site, Li1+ is bonded to six Br1- atoms to form LiBr6 octahedra that share edges with four equivalent MgBr6 octahedra and edges with six LiBr6 octahedra. There are two shorter (2.70 Å) and four longer (2.73 Å) Li–Br bond lengths. Mg2+ is bonded to six Br1- atoms to form MgBr6 octahedra that share corners with six equivalent LiBr6 octahedra, edges with two equivalent MgBr6 octahedra, and edges with six LiBr6 octahedra. The corner-sharing octahedra tilt angles range from 2–5°. There are two shorter (2.62 Å) and four longer (2.77 Å) Mg–Br bond lengths. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a rectangular see-saw-like geometry to three Li1+ and one Mg2+ atom. In the second Br1- site, Br1- is bonded to three Li1+ and two equivalent Mg2+ atoms to form a mixture of edge and corner-sharing BrLi3Mg2 square pyramids.