Li2MgBr4 crystallizes in the orthorhombic Cmmm space group. Li(1) is bonded to two equivalent Br(1) and four equivalent Br(2) atoms to form LiBr6 octahedra that share corners with six equivalent Li(1)Br6 octahedra, edges with four equivalent Li(1)Br6 octahedra, and edges with four equivalent Mg(1)Br6 octahedra. The corner-sharing octahedral tilt angles are 3°. Mg(1) is bonded to two equivalent Br(2) and four equivalent Br(1) atoms to form MgBr6 octahedra that share edges with two equivalent Mg(1)Br6 octahedra and edges with eight equivalent Li(1)Br6 octahedra. There are two inequivalent Br sites. In the first Br site, Br(2) is bonded to four equivalent Li(1) and one Mg(1) atom to form a mixture of corner and edge-sharing BrLi4Mg square pyramids. In the second Br site, Br(1) is bonded in a rectangular see-saw-like geometry to two equivalent Li(1) and two equivalent Mg(1) atoms.
Li2MgBr4 crystallizes in the orthorhombic Cmmm space group. Li(1) is bonded to two equivalent Br(1) and four equivalent Br(2) atoms to form LiBr6 octahedra that share corners with six equivalent Li(1)Br6 octahedra, edges with four equivalent Li(1)Br6 octahedra, and edges with four equivalent Mg(1)Br6 octahedra. The corner-sharing octahedral tilt angles are 3°. Both Li(1)-Br(1) bond lengths are 2.74 Å. All Li(1)-Br(2) bond lengths are 2.74 Å. Mg(1) is bonded to two equivalent Br(2) and four equivalent Br(1) atoms to form MgBr6 octahedra that share edges with two equivalent Mg(1)Br6 octahedra and edges with eight equivalent Li(1)Br6 octahedra. Both Mg(1)-Br(2) bond lengths are 2.67 Å. All Mg(1)-Br(1) bond lengths are 2.68 Å. There are two inequivalent Br sites. In the first Br site, Br(2) is bonded to four equivalent Li(1) and one Mg(1) atom to form a mixture of corner and edge-sharing BrLi4Mg square pyramids. In the second Br site, Br(1) is bonded in a rectangular see-saw-like geometry to two equivalent Li(1) and two equivalent Mg(1) atoms.