Mg6Ge2Si crystallizes in the orthorhombic Immm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Ge(1) and two equivalent Si(1) atoms to form MgSi2Ge2 tetrahedra that share corners with four equivalent Mg(1)Si2Ge2 tetrahedra, corners with twelve equivalent Mg(2)SiGe3 tetrahedra, edges with two equivalent Mg(1)Si2Ge2 tetrahedra, and edges with four equivalent Mg(2)SiGe3 tetrahedra. In the second Mg site, Mg(2) is bonded to three equivalent Ge(1) and one Si(1) atom to form MgSiGe3 tetrahedra that share corners with six equivalent Mg(1)Si2Ge2 tetrahedra, corners with ten equivalent Mg(2)SiGe3 tetrahedra, edges with two equivalent Mg(1)Si2Ge2 tetrahedra, and edges with four equivalent Mg(2)SiGe3 tetrahedra. Ge(1) is bonded in a body-centered cubic geometry to two equivalent Mg(1) and six equivalent Mg(2) atoms. Si(1) is bonded in a body-centered cubic geometry to four equivalent Mg(1) and four equivalent Mg(2) atoms.
Mg6Ge2Si crystallizes in the orthorhombic Immm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Ge(1) and two equivalent Si(1) atoms to form MgSi2Ge2 tetrahedra that share corners with four equivalent Mg(1)Si2Ge2 tetrahedra, corners with twelve equivalent Mg(2)SiGe3 tetrahedra, edges with two equivalent Mg(1)Si2Ge2 tetrahedra, and edges with four equivalent Mg(2)SiGe3 tetrahedra. Both Mg(1)-Ge(1) bond lengths are 2.76 Å. Both Mg(1)-Si(1) bond lengths are 2.75 Å. In the second Mg site, Mg(2) is bonded to three equivalent Ge(1) and one Si(1) atom to form MgSiGe3 tetrahedra that share corners with six equivalent Mg(1)Si2Ge2 tetrahedra, corners with ten equivalent Mg(2)SiGe3 tetrahedra, edges with two equivalent Mg(1)Si2Ge2 tetrahedra, and edges with four equivalent Mg(2)SiGe3 tetrahedra. All Mg(2)-Ge(1) bond lengths are 2.75 Å. The Mg(2)-Si(1) bond length is 2.74 Å. Ge(1) is bonded in a body-centered cubic geometry to two equivalent Mg(1) and six equivalent Mg(2) atoms. Si(1) is bonded in a body-centered cubic geometry to four equivalent Mg(1) and four equivalent Mg(2) atoms.