Mg6GaBi crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to two equivalent Mg(2), two equivalent Mg(3), one Ga(1), and two equivalent Bi(1) atoms. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Ga(1) atoms to form distorted MgMg10Ga2 cuboctahedra that share corners with six equivalent Mg(2)Mg10Ga2 cuboctahedra, edges with eight equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ga2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, and faces with six equivalent Bi(1)Mg10Ga2 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(4), two equivalent Ga(1), and two equivalent Bi(1) atoms to form distorted MgMg8Ga2Bi2 cuboctahedra that share corners with four equivalent Bi(1)Mg10Ga2 cuboctahedra, corners with ten equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, edges with two equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, edges with two equivalent Bi(1)Mg10Ga2 cuboctahedra, edges with four equivalent Mg(2)Mg10Ga2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ga2 cuboctahedra, faces with two equivalent Bi(1)Mg10Ga2 cuboctahedra, and faces with four equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra. In the fourth Mg site, Mg(4) is bonded in a distorted linear geometry to two equivalent Mg(2), four equivalent Mg(3), and two equivalent Bi(1) atoms. Ga(1) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), four equivalent Mg(3), and two equivalent Bi(1) atoms. Bi(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Ga(1) atoms to form distorted BiMg10Ga2 cuboctahedra that share corners with six equivalent Bi(1)Mg10Ga2 cuboctahedra, corners with eight equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, edges with four equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, faces with two equivalent Bi(1)Mg10Ga2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, and faces with six equivalent Mg(2)Mg10Ga2 cuboctahedra.
Mg6GaBi crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to two equivalent Mg(2), two equivalent Mg(3), one Ga(1), and two equivalent Bi(1) atoms. There is one shorter (3.19 Å) and one longer (3.22 Å) Mg(1)-Mg(2) bond length. Both Mg(1)-Mg(3) bond lengths are 3.26 Å. The Mg(1)-Ga(1) bond length is 3.03 Å. Both Mg(1)-Bi(1) bond lengths are 3.23 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Ga(1) atoms to form distorted MgMg10Ga2 cuboctahedra that share corners with six equivalent Mg(2)Mg10Ga2 cuboctahedra, edges with eight equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ga2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, and faces with six equivalent Bi(1)Mg10Ga2 cuboctahedra. Both Mg(2)-Mg(4) bond lengths are 3.22 Å. All Mg(2)-Mg(3) bond lengths are 3.23 Å. Both Mg(2)-Ga(1) bond lengths are 3.15 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(4), two equivalent Ga(1), and two equivalent Bi(1) atoms to form distorted MgMg8Ga2Bi2 cuboctahedra that share corners with four equivalent Bi(1)Mg10Ga2 cuboctahedra, corners with ten equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, edges with two equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, edges with two equivalent Bi(1)Mg10Ga2 cuboctahedra, edges with four equivalent Mg(2)Mg10Ga2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ga2 cuboctahedra, faces with two equivalent Bi(1)Mg10Ga2 cuboctahedra, and faces with four equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra. There is one shorter (3.09 Å) and one longer (3.20 Å) Mg(3)-Mg(3) bond length. There is one shorter (3.17 Å) and one longer (3.25 Å) Mg(3)-Mg(4) bond length. Both Mg(3)-Ga(1) bond lengths are 3.15 Å. There is one shorter (3.19 Å) and one longer (3.22 Å) Mg(3)-Bi(1) bond length. In the fourth Mg site, Mg(4) is bonded in a distorted linear geometry to two equivalent Mg(2), four equivalent Mg(3), and two equivalent Bi(1) atoms. Both Mg(4)-Bi(1) bond lengths are 3.15 Å. Ga(1) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), four equivalent Mg(3), and two equivalent Bi(1) atoms. Both Ga(1)-Bi(1) bond lengths are 3.37 Å. Bi(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Ga(1) atoms to form distorted BiMg10Ga2 cuboctahedra that share corners with six equivalent Bi(1)Mg10Ga2 cuboctahedra, corners with eight equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, edges with four equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, faces with two equivalent Bi(1)Mg10Ga2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ga2Bi2 cuboctahedra, and faces with six equivalent Mg(2)Mg10Ga2 cuboctahedra.