Mg14CuBi crystallizes in the orthorhombic Amm2 space group. There are eight inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2); two equivalent Mg(6); four Mg(4,4); and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Bi(1)Mg10Cu2 cuboctahedra; corners with six equivalent Mg(1)Mg12 cuboctahedra; corners with eight equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with four equivalent Mg(6)Mg11Cu cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with eight equivalent Mg(5)Mg10CuBi cuboctahedra; faces with two equivalent Mg(6)Mg11Cu cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg10Bi2 cuboctahedra; faces with four equivalent Mg(5)Mg10CuBi cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(7)Mg11Bi cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1); two equivalent Mg(7); four Mg(4,4); and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Cu(1)Mg10Bi2 cuboctahedra; corners with six equivalent Mg(2)Mg12 cuboctahedra; corners with eight equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four equivalent Mg(7)Mg11Bi cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with eight equivalent Mg(5)Mg10CuBi cuboctahedra; faces with two equivalent Mg(7)Mg11Bi cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Bi(1)Mg10Cu2 cuboctahedra; faces with four equivalent Mg(5)Mg10CuBi cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(6)Mg11Cu cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), two equivalent Cu(1), and two equivalent Bi(1) atoms to form distorted MgMg6Cu2Bi2 cuboctahedra that share corners with two equivalent Mg(7)Mg11Bi cuboctahedra, corners with two equivalent Mg(6)Mg11Cu cuboctahedra, corners with two equivalent Cu(1)Mg10Bi2 cuboctahedra, corners with two equivalent Bi(1)Mg10Cu2 cuboctahedra, corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with four equivalent Mg(4)Mg12 cuboctahedra, corners with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra, edges with two equivalent Mg(7)Mg11Bi cuboctahedra, edges with two equivalent Mg(6)Mg11Cu cuboctahedra, edges with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra, edges with four equivalent Mg(5)Mg10CuBi cuboctahedra, faces with two equivalent Mg(7)Mg11Bi cuboctahedra, faces with two equivalent Mg(6)Mg11Cu cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra, faces with two equivalent Cu(1)Mg10Bi2 cuboctahedra, faces with two equivalent Bi(1)Mg10Cu2 cuboctahedra, and faces with eight equivalent Mg(5)Mg10CuBi cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), two equivalent Mg(6), and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; corners with four equivalent Cu(1)Mg10Bi2 cuboctahedra; corners with four equivalent Bi(1)Mg10Cu2 cuboctahedra; corners with six Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with four equivalent Mg(5)Mg10CuBi cuboctahedra; edges with four equivalent Mg(7)Mg11Bi cuboctahedra; edges with four equivalent Mg(6)Mg11Cu cuboctahedra; faces with two equivalent Mg(7)Mg11Bi cuboctahedra; faces with two equivalent Mg(6)Mg11Cu cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; and faces with eight equivalent Mg(5)Mg10CuBi cuboctahedra. In the fifth Mg site, Mg(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), two equivalent Mg(6), and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra, corners with four equivalent Cu(1)Mg10Bi2 cuboctahedra, corners with four equivalent Bi(1)Mg10Cu2 cuboctahedra, corners with six equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(5)Mg10CuBi cuboctahedra, edges with four equivalent Mg(7)Mg11Bi cuboctahedra, edges with four equivalent Mg(6)Mg11Cu cuboctahedra, faces with two equivalent Mg(7)Mg11Bi cuboctahedra, faces with two equivalent Mg(6)Mg11Cu cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra, and faces with eight equivalent Mg(5)Mg10CuBi cuboctahedra. In the sixth Mg site, Mg(5) is bonded to one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), one Cu(1), and one Bi(1) atom to form distorted MgMg10CuBi cuboctahedra that share corners with four equivalent Mg(7)Mg11Bi cuboctahedra; corners with four equivalent Mg(6)Mg11Cu cuboctahedra; corners with ten equivalent Mg(5)Mg10CuBi cuboctahedra; edges with two equivalent Mg(5)Mg10CuBi cuboctahedra; edges with two equivalent Mg(7)Mg11Bi cuboctahedra; edges with two equivalent Mg(6)Mg11Cu cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; edges with two equivalent Cu(1)Mg10Bi2 cuboctahedra; edges with two equivalent Bi(1)Mg10Cu2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg10Bi2 cuboctahedra;  a faceface with one Bi(1)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(7)Mg11Bi cuboctahedra; faces with two equivalent Mg(6)Mg11Cu cuboctahedra; faces with four equivalent Mg(5)Mg10CuBi cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra. In the seventh Mg site, Mg(6) is bonded to one Mg(1); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(7); four equivalent Mg(5); and one Cu(1) atom to form distorted MgMg11Cu cuboctahedra that share corners with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; corners with four equivalent Mg(7)Mg11Bi cuboctahedra; corners with six equivalent Mg(6)Mg11Cu cuboctahedra; corners with eight equivalent Mg(5)Mg10CuBi cuboctahedra; edges with two equivalent Mg(7)Mg11Bi cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; edges with two equivalent Cu(1)Mg10Bi2 cuboctahedra; edges with four equivalent Mg(5)Mg10CuBi cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg10Bi2 cuboctahedra; faces with two equivalent Mg(7)Mg11Bi cuboctahedra; faces with two equivalent Mg(6)Mg11Cu cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; faces with three equivalent Mg(2)Mg12 cuboctahedra; faces with three equivalent Bi(1)Mg10Cu2 cuboctahedra; and faces with four equivalent Mg(5)Mg10CuBi cuboctahedra. In the eighth Mg site, Mg(7) is bonded to one Mg(2); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(6); four equivalent Mg(5); and one Bi(1) atom to form distorted MgMg11Bi cuboctahedra that share corners with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; corners with four equivalent Mg(6)Mg11Cu cuboctahedra; corners with six equivalent Mg(7)Mg11Bi cuboctahedra; corners with eight equivalent Mg(5)Mg10CuBi cuboctahedra; edges with two equivalent Mg(6)Mg11Cu cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; edges with two equivalent Bi(1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(5)Mg10CuBi cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Bi(1)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(7)Mg11Bi cuboctahedra; faces with two equivalent Mg(6)Mg11Cu cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; faces with three equivalent Mg(1)Mg12 cuboctahedra; faces with three equivalent Cu(1)Mg10Bi2 cuboctahedra; and faces with four equivalent Mg(5)Mg10CuBi cuboctahedra. Cu(1) is bonded to two equivalent Mg(6), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Bi(1) atoms to form CuMg10Bi2 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; corners with six equivalent Cu(1)Mg10Bi2 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Bi(1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(6)Mg11Cu cuboctahedra; edges with eight equivalent Mg(5)Mg10CuBi cuboctahedra; faces with two equivalent Mg(6)Mg11Cu cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Bi(1)Mg10Cu2 cuboctahedra; faces with four equivalent Mg(5)Mg10CuBi cuboctahedra; faces with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; and faces with six equivalent Mg(7)Mg11Bi cuboctahedra. Bi(1) is bonded to two equivalent Mg(7), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Cu(1) atoms to form BiMg10Cu2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; corners with six equivalent Bi(1)Mg10Cu2 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Cu(1)Mg10Bi2 cuboctahedra; edges with four equivalent Mg(7)Mg11Bi cuboctahedra; edges with eight equivalent Mg(5)Mg10CuBi cuboctahedra; faces with two equivalent Mg(7)Mg11Bi cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg10Bi2 cuboctahedra; faces with four equivalent Mg(5)Mg10CuBi cuboctahedra; faces with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; and faces with six equivalent Mg(6)Mg11Cu cuboctahedra.
Mg14CuBi crystallizes in the orthorhombic Amm2 space group. There are eight inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2); two equivalent Mg(6); four Mg(4,4); and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Bi(1)Mg10Cu2 cuboctahedra; corners with six equivalent Mg(1)Mg12 cuboctahedra; corners with eight equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with four equivalent Mg(6)Mg11Cu cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with eight equivalent Mg(5)Mg10CuBi cuboctahedra; faces with two equivalent Mg(6)Mg11Cu cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg10Bi2 cuboctahedra; faces with four equivalent Mg(5)Mg10CuBi cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(7)Mg11Bi cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.16 Å. Both Mg(1)-Mg(6) bond lengths are 3.20 Å. There are two shorter (3.15 Å) and two longer (3.17 Å) Mg(1)-Mg(4,4) bond lengths. All Mg(1)-Mg(5) bond lengths are 3.17 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1); two equivalent Mg(7); four Mg(4,4); and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Cu(1)Mg10Bi2 cuboctahedra; corners with six equivalent Mg(2)Mg12 cuboctahedra; corners with eight equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four equivalent Mg(7)Mg11Bi cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with eight equivalent Mg(5)Mg10CuBi cuboctahedra; faces with two equivalent Mg(7)Mg11Bi cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Bi(1)Mg10Cu2 cuboctahedra; faces with four equivalent Mg(5)Mg10CuBi cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(6)Mg11Cu cuboctahedra. Both Mg(2)-Mg(7) bond lengths are 3.14 Å. There are two shorter (3.14 Å) and two longer (3.18 Å) Mg(2)-Mg(4,4) bond lengths. All Mg(2)-Mg(5) bond lengths are 3.21 Å. In the third Mg site, Mg(3) is bonded to two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), two equivalent Cu(1), and two equivalent Bi(1) atoms to form distorted MgMg6Cu2Bi2 cuboctahedra that share corners with two equivalent Mg(7)Mg11Bi cuboctahedra, corners with two equivalent Mg(6)Mg11Cu cuboctahedra, corners with two equivalent Cu(1)Mg10Bi2 cuboctahedra, corners with two equivalent Bi(1)Mg10Cu2 cuboctahedra, corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with four equivalent Mg(4)Mg12 cuboctahedra, corners with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra, edges with two equivalent Mg(7)Mg11Bi cuboctahedra, edges with two equivalent Mg(6)Mg11Cu cuboctahedra, edges with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra, edges with four equivalent Mg(5)Mg10CuBi cuboctahedra, faces with two equivalent Mg(7)Mg11Bi cuboctahedra, faces with two equivalent Mg(6)Mg11Cu cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra, faces with two equivalent Cu(1)Mg10Bi2 cuboctahedra, faces with two equivalent Bi(1)Mg10Cu2 cuboctahedra, and faces with eight equivalent Mg(5)Mg10CuBi cuboctahedra. Both Mg(3)-Mg(5) bond lengths are 3.17 Å. Both Mg(3)-Mg(6) bond lengths are 3.15 Å. Both Mg(3)-Mg(7) bond lengths are 3.22 Å. Both Mg(3)-Cu(1) bond lengths are 3.16 Å. There is one shorter (3.14 Å) and one longer (3.18 Å) Mg(3)-Bi(1) bond length. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), two equivalent Mg(6), and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; corners with four equivalent Cu(1)Mg10Bi2 cuboctahedra; corners with four equivalent Bi(1)Mg10Cu2 cuboctahedra; corners with six Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with four equivalent Mg(5)Mg10CuBi cuboctahedra; edges with four equivalent Mg(7)Mg11Bi cuboctahedra; edges with four equivalent Mg(6)Mg11Cu cuboctahedra; faces with two equivalent Mg(7)Mg11Bi cuboctahedra; faces with two equivalent Mg(6)Mg11Cu cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; and faces with eight equivalent Mg(5)Mg10CuBi cuboctahedra. There is one shorter (3.15 Å) and one longer (3.17 Å) Mg(4)-Mg(4) bond length. Both Mg(4)-Mg(5) bond lengths are 3.19 Å. Both Mg(4)-Mg(6) bond lengths are 3.22 Å. Both Mg(4)-Mg(7) bond lengths are 3.12 Å. In the fifth Mg site, Mg(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), two equivalent Mg(6), and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra, corners with four equivalent Cu(1)Mg10Bi2 cuboctahedra, corners with four equivalent Bi(1)Mg10Cu2 cuboctahedra, corners with six equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(5)Mg10CuBi cuboctahedra, edges with four equivalent Mg(7)Mg11Bi cuboctahedra, edges with four equivalent Mg(6)Mg11Cu cuboctahedra, faces with two equivalent Mg(7)Mg11Bi cuboctahedra, faces with two equivalent Mg(6)Mg11Cu cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra, and faces with eight equivalent Mg(5)Mg10CuBi cuboctahedra. Both Mg(4)-Mg(5) bond lengths are 3.19 Å. Both Mg(4)-Mg(6) bond lengths are 3.22 Å. Both Mg(4)-Mg(7) bond lengths are 3.12 Å. In the sixth Mg site, Mg(5) is bonded to one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), one Cu(1), and one Bi(1) atom to form distorted MgMg10CuBi cuboctahedra that share corners with four equivalent Mg(7)Mg11Bi cuboctahedra; corners with four equivalent Mg(6)Mg11Cu cuboctahedra; corners with ten equivalent Mg(5)Mg10CuBi cuboctahedra; edges with two equivalent Mg(5)Mg10CuBi cuboctahedra; edges with two equivalent Mg(7)Mg11Bi cuboctahedra; edges with two equivalent Mg(6)Mg11Cu cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; edges with two equivalent Cu(1)Mg10Bi2 cuboctahedra; edges with two equivalent Bi(1)Mg10Cu2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg10Bi2 cuboctahedra;  a faceface with one Bi(1)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(7)Mg11Bi cuboctahedra; faces with two equivalent Mg(6)Mg11Cu cuboctahedra; faces with four equivalent Mg(5)Mg10CuBi cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra. There is one shorter (3.07 Å) and one longer (3.24 Å) Mg(5)-Mg(5) bond length. There is one shorter (3.11 Å) and one longer (3.21 Å) Mg(5)-Mg(6) bond length. There is one shorter (3.12 Å) and one longer (3.20 Å) Mg(5)-Mg(7) bond length. The Mg(5)-Cu(1) bond length is 3.14 Å. The Mg(5)-Bi(1) bond length is 3.19 Å. In the seventh Mg site, Mg(6) is bonded to one Mg(1); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(7); four equivalent Mg(5); and one Cu(1) atom to form distorted MgMg11Cu cuboctahedra that share corners with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; corners with four equivalent Mg(7)Mg11Bi cuboctahedra; corners with six equivalent Mg(6)Mg11Cu cuboctahedra; corners with eight equivalent Mg(5)Mg10CuBi cuboctahedra; edges with two equivalent Mg(7)Mg11Bi cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; edges with two equivalent Cu(1)Mg10Bi2 cuboctahedra; edges with four equivalent Mg(5)Mg10CuBi cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg10Bi2 cuboctahedra; faces with two equivalent Mg(7)Mg11Bi cuboctahedra; faces with two equivalent Mg(6)Mg11Cu cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; faces with three equivalent Mg(2)Mg12 cuboctahedra; faces with three equivalent Bi(1)Mg10Cu2 cuboctahedra; and faces with four equivalent Mg(5)Mg10CuBi cuboctahedra. Both Mg(6)-Mg(7) bond lengths are 3.16 Å. The Mg(6)-Cu(1) bond length is 3.12 Å. In the eighth Mg site, Mg(7) is bonded to one Mg(2); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(6); four equivalent Mg(5); and one Bi(1) atom to form distorted MgMg11Bi cuboctahedra that share corners with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; corners with four equivalent Mg(6)Mg11Cu cuboctahedra; corners with six equivalent Mg(7)Mg11Bi cuboctahedra; corners with eight equivalent Mg(5)Mg10CuBi cuboctahedra; edges with two equivalent Mg(6)Mg11Cu cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; edges with two equivalent Bi(1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(5)Mg10CuBi cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Bi(1)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(7)Mg11Bi cuboctahedra; faces with two equivalent Mg(6)Mg11Cu cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; faces with three equivalent Mg(1)Mg12 cuboctahedra; faces with three equivalent Cu(1)Mg10Bi2 cuboctahedra; and faces with four equivalent Mg(5)Mg10CuBi cuboctahedra. The Mg(7)-Bi(1) bond length is 3.24 Å. Cu(1) is bonded to two equivalent Mg(6), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Bi(1) atoms to form CuMg10Bi2 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; corners with six equivalent Cu(1)Mg10Bi2 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Bi(1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(6)Mg11Cu cuboctahedra; edges with eight equivalent Mg(5)Mg10CuBi cuboctahedra; faces with two equivalent Mg(6)Mg11Cu cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Bi(1)Mg10Cu2 cuboctahedra; faces with four equivalent Mg(5)Mg10CuBi cuboctahedra; faces with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; and faces with six equivalent Mg(7)Mg11Bi cuboctahedra. Both Cu(1)-Bi(1) bond lengths are 3.16 Å. Bi(1) is bonded to two equivalent Mg(7), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Cu(1) atoms to form BiMg10Cu2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; corners with six equivalent Bi(1)Mg10Cu2 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Cu(1)Mg10Bi2 cuboctahedra; edges with four equivalent Mg(7)Mg11Bi cuboctahedra; edges with eight equivalent Mg(5)Mg10CuBi cuboctahedra; faces with two equivalent Mg(7)Mg11Bi cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg10Bi2 cuboctahedra; faces with four equivalent Mg(5)Mg10CuBi cuboctahedra; faces with four equivalent Mg(3)Mg6Cu2Bi2 cuboctahedra; and faces with six equivalent Mg(6)Mg11Cu cuboctahedra.