Mg5Ge crystallizes in the orthorhombic Amm2 space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and four equivalent Ge(1) atoms to form distorted MgMg8Ge4 cuboctahedra that share corners with six equivalent Mg(2)Mg10Ge2 cuboctahedra, corners with six equivalent Mg(3)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg8Ge4 cuboctahedra, edges with three equivalent Mg(2)Mg10Ge2 cuboctahedra, edges with three equivalent Mg(3)Mg12 cuboctahedra, faces with two equivalent Mg(2)Mg10Ge2 cuboctahedra, faces with two equivalent Mg(3)Mg12 cuboctahedra, faces with four equivalent Mg(1)Mg8Ge4 cuboctahedra, and faces with six equivalent Mg(4)Mg6Ge2 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), four equivalent Mg(5), and two equivalent Ge(1) atoms to form distorted MgMg10Ge2 cuboctahedra that share corners with four equivalent Mg(4)Mg6Ge2 cuboctahedra, corners with six equivalent Mg(2)Mg10Ge2 cuboctahedra, corners with six equivalent Mg(3)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg8Ge4 cuboctahedra, edges with three equivalent Mg(3)Mg12 cuboctahedra, edges with three equivalent Mg(1)Mg8Ge4 cuboctahedra, edges with six equivalent Mg(4)Mg6Ge2 cuboctahedra, faces with two equivalent Mg(3)Mg12 cuboctahedra, faces with two equivalent Mg(1)Mg8Ge4 cuboctahedra, and faces with four equivalent Mg(2)Mg10Ge2 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(5), and four equivalent Mg(4) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Mg(4)Mg6Ge2 cuboctahedra, corners with six equivalent Mg(2)Mg10Ge2 cuboctahedra, corners with six equivalent Mg(3)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg8Ge4 cuboctahedra, edges with three equivalent Mg(2)Mg10Ge2 cuboctahedra, edges with three equivalent Mg(1)Mg8Ge4 cuboctahedra, edges with four equivalent Mg(4)Mg6Ge2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ge2 cuboctahedra, faces with two equivalent Mg(1)Mg8Ge4 cuboctahedra, and faces with four equivalent Mg(3)Mg12 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1), four equivalent Mg(3), and two equivalent Ge(1) atoms to form distorted MgMg6Ge2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Ge2 cuboctahedra, corners with four equivalent Mg(3)Mg12 cuboctahedra, corners with four equivalent Mg(4)Mg6Ge2 cuboctahedra, edges with four equivalent Mg(3)Mg12 cuboctahedra, edges with six equivalent Mg(2)Mg10Ge2 cuboctahedra, faces with four equivalent Mg(4)Mg6Ge2 cuboctahedra, and faces with six equivalent Mg(1)Mg8Ge4 cuboctahedra. In the fifth Mg site, Mg(5) is bonded in a 2-coordinate geometry to two equivalent Mg(3), four equivalent Mg(2), and two equivalent Ge(1) atoms. Ge(1) is bonded in a 10-coordinate geometry to two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), and four equivalent Mg(1) atoms.
Mg5Ge crystallizes in the orthorhombic Amm2 space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and four equivalent Ge(1) atoms to form distorted MgMg8Ge4 cuboctahedra that share corners with six equivalent Mg(2)Mg10Ge2 cuboctahedra, corners with six equivalent Mg(3)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg8Ge4 cuboctahedra, edges with three equivalent Mg(2)Mg10Ge2 cuboctahedra, edges with three equivalent Mg(3)Mg12 cuboctahedra, faces with two equivalent Mg(2)Mg10Ge2 cuboctahedra, faces with two equivalent Mg(3)Mg12 cuboctahedra, faces with four equivalent Mg(1)Mg8Ge4 cuboctahedra, and faces with six equivalent Mg(4)Mg6Ge2 cuboctahedra. Both Mg(1)-Mg(1) bond lengths are 3.17 Å. Both Mg(1)-Mg(2) bond lengths are 3.01 Å. Both Mg(1)-Mg(3) bond lengths are 3.16 Å. Both Mg(1)-Mg(4) bond lengths are 3.11 Å. All Mg(1)-Ge(1) bond lengths are 3.12 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), four equivalent Mg(5), and two equivalent Ge(1) atoms to form distorted MgMg10Ge2 cuboctahedra that share corners with four equivalent Mg(4)Mg6Ge2 cuboctahedra, corners with six equivalent Mg(2)Mg10Ge2 cuboctahedra, corners with six equivalent Mg(3)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg8Ge4 cuboctahedra, edges with three equivalent Mg(3)Mg12 cuboctahedra, edges with three equivalent Mg(1)Mg8Ge4 cuboctahedra, edges with six equivalent Mg(4)Mg6Ge2 cuboctahedra, faces with two equivalent Mg(3)Mg12 cuboctahedra, faces with two equivalent Mg(1)Mg8Ge4 cuboctahedra, and faces with four equivalent Mg(2)Mg10Ge2 cuboctahedra. Both Mg(2)-Mg(2) bond lengths are 3.17 Å. Both Mg(2)-Mg(3) bond lengths are 3.10 Å. All Mg(2)-Mg(5) bond lengths are 3.11 Å. Both Mg(2)-Ge(1) bond lengths are 3.09 Å. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(5), and four equivalent Mg(4) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Mg(4)Mg6Ge2 cuboctahedra, corners with six equivalent Mg(2)Mg10Ge2 cuboctahedra, corners with six equivalent Mg(3)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg8Ge4 cuboctahedra, edges with three equivalent Mg(2)Mg10Ge2 cuboctahedra, edges with three equivalent Mg(1)Mg8Ge4 cuboctahedra, edges with four equivalent Mg(4)Mg6Ge2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ge2 cuboctahedra, faces with two equivalent Mg(1)Mg8Ge4 cuboctahedra, and faces with four equivalent Mg(3)Mg12 cuboctahedra. Both Mg(3)-Mg(3) bond lengths are 3.17 Å. Both Mg(3)-Mg(5) bond lengths are 3.18 Å. All Mg(3)-Mg(4) bond lengths are 3.16 Å. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1), four equivalent Mg(3), and two equivalent Ge(1) atoms to form distorted MgMg6Ge2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Ge2 cuboctahedra, corners with four equivalent Mg(3)Mg12 cuboctahedra, corners with four equivalent Mg(4)Mg6Ge2 cuboctahedra, edges with four equivalent Mg(3)Mg12 cuboctahedra, edges with six equivalent Mg(2)Mg10Ge2 cuboctahedra, faces with four equivalent Mg(4)Mg6Ge2 cuboctahedra, and faces with six equivalent Mg(1)Mg8Ge4 cuboctahedra. Both Mg(4)-Ge(1) bond lengths are 3.03 Å. In the fifth Mg site, Mg(5) is bonded in a 2-coordinate geometry to two equivalent Mg(3), four equivalent Mg(2), and two equivalent Ge(1) atoms. Both Mg(5)-Ge(1) bond lengths are 2.97 Å. Ge(1) is bonded in a 10-coordinate geometry to two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), and four equivalent Mg(1) atoms.