Mg14MnCu crystallizes in the hexagonal P-6m2 space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(4); four Mg(1,1); four equivalent Mg(3); and two equivalent Mn(1) atoms to form MgMg10Mn2 cuboctahedra that share corners with four equivalent Cu(1)Mg12 cuboctahedra; corners with six equivalent Mg(1)Mg10Mn2 cuboctahedra; corners with eight equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with two equivalent Mn(1)Mg12 cuboctahedra; edges with four Mg(1,1)Mg10Mn2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with eight equivalent Mg(3)Mg10MnCu cuboctahedra; faces with two equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mn(1)Mg12 cuboctahedra; faces with four Mg(1,1)Mg10Mn2 cuboctahedra; and faces with ten equivalent Mg(3)Mg10MnCu cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(2), four equivalent Mg(3), and two equivalent Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent Mn(1)Mg12 cuboctahedra; corners with six equivalent Mg(2)Mg10Cu2 cuboctahedra; corners with eight Mg(1,1)Mg10Mn2 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with eight equivalent Mg(3)Mg10MnCu cuboctahedra; faces with two equivalent Mg(1)Mg10Mn2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with four equivalent Mg(2)Mg10Cu2 cuboctahedra; and faces with ten equivalent Mg(3)Mg10MnCu cuboctahedra. In the third Mg site, Mg(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Mn(1) atoms to form MgMg10Mn2 cuboctahedra that share corners with four equivalent Cu(1)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg10Mn2 cuboctahedra, corners with eight equivalent Mg(2)Mg10Cu2 cuboctahedra, edges with two equivalent Mn(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(3)Mg10MnCu cuboctahedra, faces with two equivalent Mg(2)Mg10Cu2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mn(1)Mg12 cuboctahedra, faces with four equivalent Mg(1)Mg10Mn2 cuboctahedra, and faces with ten equivalent Mg(3)Mg10MnCu cuboctahedra. In the fourth Mg site, Mg(3) is bonded to two Mg(1,1); two equivalent Mg(2); two equivalent Mg(4); four equivalent Mg(3); one Mn(1); and one Cu(1) atom to form distorted MgMg10MnCu cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with fourteen equivalent Mg(3)Mg10MnCu cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with two equivalent Mn(1)Mg12 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with four Mg(1,1)Mg10Mn2 cuboctahedra; edges with four equivalent Mg(3)Mg10MnCu cuboctahedra;  a faceface with one Mn(1)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with five equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with five Mg(1,1)Mg10Mn2 cuboctahedra; and faces with six equivalent Mg(3)Mg10MnCu cuboctahedra. In the fifth Mg site, Mg(4) is bonded to three Mg(1,1); three equivalent Mg(2); and six equivalent Mg(3) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra; corners with twelve equivalent Mg(3)Mg10MnCu cuboctahedra; edges with six equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with six Mg(1,1)Mg10Mn2 cuboctahedra; edges with six equivalent Mg(3)Mg10MnCu cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with three equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with three Mg(1,1)Mg10Mn2 cuboctahedra; faces with three equivalent Mn(1)Mg12 cuboctahedra; faces with three equivalent Cu(1)Mg12 cuboctahedra; and faces with six equivalent Mg(3)Mg10MnCu cuboctahedra. Mn(1) is bonded to six Mg(1,1) and six equivalent Mg(3) atoms to form MnMg12 cuboctahedra that share corners with six equivalent Mn(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with six Mg(1,1)Mg10Mn2 cuboctahedra; edges with twelve equivalent Mg(3)Mg10MnCu cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six Mg(1,1)Mg10Mn2 cuboctahedra; faces with six equivalent Mg(3)Mg10MnCu cuboctahedra; and faces with six equivalent Mg(4)Mg12 cuboctahedra. Cu(1) is bonded to six equivalent Mg(2) and six equivalent Mg(3) atoms to form CuMg12 cuboctahedra that share corners with six equivalent Cu(1)Mg12 cuboctahedra; corners with twelve Mg(1,1)Mg10Mn2 cuboctahedra; edges with six equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with twelve equivalent Mg(3)Mg10MnCu cuboctahedra; faces with two equivalent Mn(1)Mg12 cuboctahedra; faces with six equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with six equivalent Mg(3)Mg10MnCu cuboctahedra; and faces with six equivalent Mg(4)Mg12 cuboctahedra.
Mg14MnCu crystallizes in the hexagonal P-6m2 space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(4); four Mg(1,1); four equivalent Mg(3); and two equivalent Mn(1) atoms to form MgMg10Mn2 cuboctahedra that share corners with four equivalent Cu(1)Mg12 cuboctahedra; corners with six equivalent Mg(1)Mg10Mn2 cuboctahedra; corners with eight equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with two equivalent Mn(1)Mg12 cuboctahedra; edges with four Mg(1,1)Mg10Mn2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with eight equivalent Mg(3)Mg10MnCu cuboctahedra; faces with two equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mn(1)Mg12 cuboctahedra; faces with four Mg(1,1)Mg10Mn2 cuboctahedra; and faces with ten equivalent Mg(3)Mg10MnCu cuboctahedra. Both Mg(1)-Mg(4) bond lengths are 3.07 Å. There are two shorter (3.11 Å) and two longer (3.15 Å) Mg(1)-Mg(1,1) bond lengths. All Mg(1)-Mg(3) bond lengths are 3.10 Å. Both Mg(1)-Mn(1) bond lengths are 3.13 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(2), four equivalent Mg(3), and two equivalent Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent Mn(1)Mg12 cuboctahedra; corners with six equivalent Mg(2)Mg10Cu2 cuboctahedra; corners with eight Mg(1,1)Mg10Mn2 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with eight equivalent Mg(3)Mg10MnCu cuboctahedra; faces with two equivalent Mg(1)Mg10Mn2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with four equivalent Mg(2)Mg10Cu2 cuboctahedra; and faces with ten equivalent Mg(3)Mg10MnCu cuboctahedra. Both Mg(2)-Mg(4) bond lengths are 3.07 Å. There are two shorter (3.12 Å) and two longer (3.14 Å) Mg(2)-Mg(2) bond lengths. All Mg(2)-Mg(3) bond lengths are 3.08 Å. Both Mg(2)-Cu(1) bond lengths are 3.13 Å. In the third Mg site, Mg(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Mn(1) atoms to form MgMg10Mn2 cuboctahedra that share corners with four equivalent Cu(1)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg10Mn2 cuboctahedra, corners with eight equivalent Mg(2)Mg10Cu2 cuboctahedra, edges with two equivalent Mn(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(3)Mg10MnCu cuboctahedra, faces with two equivalent Mg(2)Mg10Cu2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mn(1)Mg12 cuboctahedra, faces with four equivalent Mg(1)Mg10Mn2 cuboctahedra, and faces with ten equivalent Mg(3)Mg10MnCu cuboctahedra. Both Mg(1)-Mg(4) bond lengths are 3.07 Å. All Mg(1)-Mg(3) bond lengths are 3.10 Å. Both Mg(1)-Mn(1) bond lengths are 3.13 Å. In the fourth Mg site, Mg(3) is bonded to two Mg(1,1); two equivalent Mg(2); two equivalent Mg(4); four equivalent Mg(3); one Mn(1); and one Cu(1) atom to form distorted MgMg10MnCu cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with fourteen equivalent Mg(3)Mg10MnCu cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with two equivalent Mn(1)Mg12 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with four Mg(1,1)Mg10Mn2 cuboctahedra; edges with four equivalent Mg(3)Mg10MnCu cuboctahedra;  a faceface with one Mn(1)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with five equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with five Mg(1,1)Mg10Mn2 cuboctahedra; and faces with six equivalent Mg(3)Mg10MnCu cuboctahedra. Both Mg(3)-Mg(4) bond lengths are 3.13 Å. There are two shorter (3.03 Å) and two longer (3.23 Å) Mg(3)-Mg(3) bond lengths. The Mg(3)-Mn(1) bond length is 3.05 Å. The Mg(3)-Cu(1) bond length is 3.02 Å. In the fifth Mg site, Mg(4) is bonded to three Mg(1,1); three equivalent Mg(2); and six equivalent Mg(3) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra; corners with twelve equivalent Mg(3)Mg10MnCu cuboctahedra; edges with six equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with six Mg(1,1)Mg10Mn2 cuboctahedra; edges with six equivalent Mg(3)Mg10MnCu cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with three equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with three Mg(1,1)Mg10Mn2 cuboctahedra; faces with three equivalent Mn(1)Mg12 cuboctahedra; faces with three equivalent Cu(1)Mg12 cuboctahedra; and faces with six equivalent Mg(3)Mg10MnCu cuboctahedra. Mn(1) is bonded to six Mg(1,1) and six equivalent Mg(3) atoms to form MnMg12 cuboctahedra that share corners with six equivalent Mn(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with six Mg(1,1)Mg10Mn2 cuboctahedra; edges with twelve equivalent Mg(3)Mg10MnCu cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six Mg(1,1)Mg10Mn2 cuboctahedra; faces with six equivalent Mg(3)Mg10MnCu cuboctahedra; and faces with six equivalent Mg(4)Mg12 cuboctahedra. Cu(1) is bonded to six equivalent Mg(2) and six equivalent Mg(3) atoms to form CuMg12 cuboctahedra that share corners with six equivalent Cu(1)Mg12 cuboctahedra; corners with twelve Mg(1,1)Mg10Mn2 cuboctahedra; edges with six equivalent Mg(2)Mg10Cu2 cuboctahedra; edges with twelve equivalent Mg(3)Mg10MnCu cuboctahedra; faces with two equivalent Mn(1)Mg12 cuboctahedra; faces with six equivalent Mg(2)Mg10Cu2 cuboctahedra; faces with six equivalent Mg(3)Mg10MnCu cuboctahedra; and faces with six equivalent Mg(4)Mg12 cuboctahedra.