Mg14VCu 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 equivalent Mg(1); four Mg(3,3); and two equivalent Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent V(1)Mg12 cuboctahedra; corners with six equivalent Mg(1)Mg10Cu2 cuboctahedra; corners with eight equivalent Mg(2)Mg10V2 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with eight Mg(3,3)Mg10VCu cuboctahedra; faces with two equivalent Mg(2)Mg10V2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with four equivalent Mg(1)Mg10Cu2 cuboctahedra; and faces with ten Mg(3,3)Mg10VCu cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4); four equivalent Mg(2); four Mg(3,3); and two equivalent V(1) atoms to form distorted MgMg10V2 cuboctahedra that share corners with four equivalent Cu(1)Mg12 cuboctahedra; corners with six equivalent Mg(2)Mg10V2 cuboctahedra; corners with eight equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with two equivalent V(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10V2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with eight Mg(3,3)Mg10VCu cuboctahedra; faces with two equivalent Mg(1)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent V(1)Mg12 cuboctahedra; faces with four equivalent Mg(2)Mg10V2 cuboctahedra; and faces with ten Mg(3,3)Mg10VCu cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), four equivalent Mg(3), one V(1), and one Cu(1) atom to form distorted MgMg10VCu cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with fourteen Mg(3,3)Mg10VCu cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with two equivalent V(1)Mg12 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(2)Mg10V2 cuboctahedra; edges with four equivalent Mg(3)Mg10VCu cuboctahedra;  a faceface with one V(1)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with five equivalent Mg(1)Mg10Cu2 cuboctahedra; faces with five equivalent Mg(2)Mg10V2 cuboctahedra; and faces with six Mg(3,3)Mg10VCu cuboctahedra. In the fourth Mg site, Mg(3) is bonded to two equivalent Mg(1); two equivalent Mg(2); two equivalent Mg(4); four Mg(3,3); one V(1); and one Cu(1) atom to form distorted MgMg10VCu cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with fourteen Mg(3,3)Mg10VCu cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with two equivalent V(1)Mg12 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(2)Mg10V2 cuboctahedra; edges with four Mg(3,3)Mg10VCu cuboctahedra;  a faceface with one V(1)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with five equivalent Mg(1)Mg10Cu2 cuboctahedra; faces with five equivalent Mg(2)Mg10V2 cuboctahedra; and faces with six Mg(3,3)Mg10VCu cuboctahedra. In the fifth Mg site, Mg(4) is bonded to three equivalent Mg(1); three equivalent Mg(2); and six Mg(3,3) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra; corners with twelve Mg(3,3)Mg10VCu cuboctahedra; edges with six equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with six equivalent Mg(2)Mg10V2 cuboctahedra; edges with six Mg(3,3)Mg10VCu cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with three equivalent Mg(1)Mg10Cu2 cuboctahedra; faces with three equivalent Mg(2)Mg10V2 cuboctahedra; faces with three equivalent V(1)Mg12 cuboctahedra; faces with three equivalent Cu(1)Mg12 cuboctahedra; and faces with six Mg(3,3)Mg10VCu cuboctahedra. V(1) is bonded to six equivalent Mg(2) and six Mg(3,3) atoms to form VMg12 cuboctahedra that share corners with six equivalent V(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with six equivalent Mg(2)Mg10V2 cuboctahedra; edges with twelve Mg(3,3)Mg10VCu cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six equivalent Mg(2)Mg10V2 cuboctahedra; faces with six Mg(3,3)Mg10VCu cuboctahedra; and faces with six equivalent Mg(4)Mg12 cuboctahedra. Cu(1) is bonded to six equivalent Mg(1) and six Mg(3,3) atoms to form CuMg12 cuboctahedra that share corners with six equivalent Cu(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(2)Mg10V2 cuboctahedra; edges with six equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with twelve Mg(3,3)Mg10VCu cuboctahedra; faces with two equivalent V(1)Mg12 cuboctahedra; faces with six equivalent Mg(1)Mg10Cu2 cuboctahedra; faces with six Mg(3,3)Mg10VCu cuboctahedra; and faces with six equivalent Mg(4)Mg12 cuboctahedra.
Mg14VCu 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 equivalent Mg(1); four Mg(3,3); and two equivalent Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent V(1)Mg12 cuboctahedra; corners with six equivalent Mg(1)Mg10Cu2 cuboctahedra; corners with eight equivalent Mg(2)Mg10V2 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with eight Mg(3,3)Mg10VCu cuboctahedra; faces with two equivalent Mg(2)Mg10V2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with four equivalent Mg(1)Mg10Cu2 cuboctahedra; and faces with ten Mg(3,3)Mg10VCu cuboctahedra. Both Mg(1)-Mg(4) bond lengths are 3.09 Å. There are two shorter (3.11 Å) and two longer (3.14 Å) Mg(1)-Mg(1) bond lengths. All Mg(1)-Mg(3,3) bond lengths are 3.08 Å. Both Mg(1)-Cu(1) bond lengths are 3.12 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4); four equivalent Mg(2); four Mg(3,3); and two equivalent V(1) atoms to form distorted MgMg10V2 cuboctahedra that share corners with four equivalent Cu(1)Mg12 cuboctahedra; corners with six equivalent Mg(2)Mg10V2 cuboctahedra; corners with eight equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with two equivalent V(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10V2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; edges with eight Mg(3,3)Mg10VCu cuboctahedra; faces with two equivalent Mg(1)Mg10Cu2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent V(1)Mg12 cuboctahedra; faces with four equivalent Mg(2)Mg10V2 cuboctahedra; and faces with ten Mg(3,3)Mg10VCu cuboctahedra. Both Mg(2)-Mg(4) bond lengths are 3.08 Å. There are two shorter (3.09 Å) and two longer (3.16 Å) Mg(2)-Mg(2) bond lengths. All Mg(2)-Mg(3,3) bond lengths are 3.13 Å. Both Mg(2)-V(1) bond lengths are 3.12 Å. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), four equivalent Mg(3), one V(1), and one Cu(1) atom to form distorted MgMg10VCu cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with fourteen Mg(3,3)Mg10VCu cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with two equivalent V(1)Mg12 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(2)Mg10V2 cuboctahedra; edges with four equivalent Mg(3)Mg10VCu cuboctahedra;  a faceface with one V(1)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with five equivalent Mg(1)Mg10Cu2 cuboctahedra; faces with five equivalent Mg(2)Mg10V2 cuboctahedra; and faces with six Mg(3,3)Mg10VCu cuboctahedra. Both Mg(3)-Mg(4) bond lengths are 3.13 Å. There are two shorter (3.00 Å) and two longer (3.25 Å) Mg(3)-Mg(3) bond lengths. The Mg(3)-V(1) bond length is 3.07 Å. The Mg(3)-Cu(1) bond length is 3.01 Å. In the fourth Mg site, Mg(3) is bonded to two equivalent Mg(1); two equivalent Mg(2); two equivalent Mg(4); four Mg(3,3); one V(1); and one Cu(1) atom to form distorted MgMg10VCu cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra; corners with fourteen Mg(3,3)Mg10VCu cuboctahedra; edges with two equivalent Mg(4)Mg12 cuboctahedra; edges with two equivalent V(1)Mg12 cuboctahedra; edges with two equivalent Cu(1)Mg12 cuboctahedra; edges with four equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with four equivalent Mg(2)Mg10V2 cuboctahedra; edges with four Mg(3,3)Mg10VCu cuboctahedra;  a faceface with one V(1)Mg12 cuboctahedra;  a faceface with one Cu(1)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with five equivalent Mg(1)Mg10Cu2 cuboctahedra; faces with five equivalent Mg(2)Mg10V2 cuboctahedra; and faces with six Mg(3,3)Mg10VCu cuboctahedra. Both Mg(3)-Mg(4) bond lengths are 3.13 Å. There is one shorter (3.00 Å) and one longer (3.25 Å) Mg(3)-Mg(3) bond length. The Mg(3)-V(1) bond length is 3.07 Å. The Mg(3)-Cu(1) bond length is 3.01 Å. In the fifth Mg site, Mg(4) is bonded to three equivalent Mg(1); three equivalent Mg(2); and six Mg(3,3) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra; corners with twelve Mg(3,3)Mg10VCu cuboctahedra; edges with six equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with six equivalent Mg(2)Mg10V2 cuboctahedra; edges with six Mg(3,3)Mg10VCu cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with three equivalent Mg(1)Mg10Cu2 cuboctahedra; faces with three equivalent Mg(2)Mg10V2 cuboctahedra; faces with three equivalent V(1)Mg12 cuboctahedra; faces with three equivalent Cu(1)Mg12 cuboctahedra; and faces with six Mg(3,3)Mg10VCu cuboctahedra. V(1) is bonded to six equivalent Mg(2) and six Mg(3,3) atoms to form VMg12 cuboctahedra that share corners with six equivalent V(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with six equivalent Mg(2)Mg10V2 cuboctahedra; edges with twelve Mg(3,3)Mg10VCu cuboctahedra; faces with two equivalent Cu(1)Mg12 cuboctahedra; faces with six equivalent Mg(2)Mg10V2 cuboctahedra; faces with six Mg(3,3)Mg10VCu cuboctahedra; and faces with six equivalent Mg(4)Mg12 cuboctahedra. Cu(1) is bonded to six equivalent Mg(1) and six Mg(3,3) atoms to form CuMg12 cuboctahedra that share corners with six equivalent Cu(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(2)Mg10V2 cuboctahedra; edges with six equivalent Mg(1)Mg10Cu2 cuboctahedra; edges with twelve Mg(3,3)Mg10VCu cuboctahedra; faces with two equivalent V(1)Mg12 cuboctahedra; faces with six equivalent Mg(1)Mg10Cu2 cuboctahedra; faces with six Mg(3,3)Mg10VCu cuboctahedra; and faces with six equivalent Mg(4)Mg12 cuboctahedra.