Mg14VCu crystallizes in the orthorhombic Amm2 space group. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2), two equivalent Mg(6), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent V(1)Mg10Cu2 cuboctahedra, corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Mg8V2Cu2 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(5)Mg10VCu cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Cu(1)Mg10V2 cuboctahedra, faces with four equivalent Mg(5)Mg10VCu cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with six equivalent Mg(7)Mg11V cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(7), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Cu(1)Mg10V2 cuboctahedra, corners with six equivalent Mg(2)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Mg8V2Cu2 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(7)Mg11V cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(5)Mg10VCu cuboctahedra, faces with two equivalent Mg(7)Mg11V cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent V(1)Mg10Cu2 cuboctahedra, faces with four equivalent Mg(5)Mg10VCu cuboctahedra, and faces with four equivalent Mg(4)Mg12 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(3), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), two equivalent V(1), and two equivalent Cu(1) atoms to form distorted MgMg8V2Cu2 cuboctahedra that share 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 six equivalent Mg(3)Mg8V2Cu2 cuboctahedra, edges with two equivalent Mg(3)Mg8V2Cu2 cuboctahedra, edges with two equivalent V(1)Mg10Cu2 cuboctahedra, edges with two equivalent Cu(1)Mg10V2 cuboctahedra, edges with four equivalent Mg(5)Mg10VCu cuboctahedra, edges with four equivalent Mg(7)Mg11V cuboctahedra, faces with two equivalent Mg(7)Mg11V cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Mg8V2Cu2 cuboctahedra, faces with two equivalent V(1)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10V2 cuboctahedra, and faces with eight equivalent Mg(5)Mg10VCu 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)Mg8V2Cu2 cuboctahedra, corners with four equivalent V(1)Mg10Cu2 cuboctahedra, corners with four equivalent Cu(1)Mg10V2 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)Mg10VCu cuboctahedra, edges with four equivalent Mg(7)Mg11V cuboctahedra, faces with two equivalent Mg(7)Mg11V 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)Mg8V2Cu2 cuboctahedra, and faces with eight equivalent Mg(5)Mg10VCu cuboctahedra. In the fifth 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 V(1), and one Cu(1) atom to form distorted MgMg10VCu cuboctahedra that share corners with four equivalent Mg(7)Mg11V cuboctahedra, corners with ten equivalent Mg(5)Mg10VCu cuboctahedra, edges with two equivalent Mg(5)Mg10VCu cuboctahedra, edges with two equivalent Mg(7)Mg11V 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)Mg8V2Cu2 cuboctahedra, edges with two equivalent V(1)Mg10Cu2 cuboctahedra, edges with two equivalent Cu(1)Mg10V2 cuboctahedra,  a faceface with one Mg(1)Mg12 cuboctahedra,  a faceface with one Mg(2)Mg12 cuboctahedra,  a faceface with one V(1)Mg10Cu2 cuboctahedra,  a faceface with one Cu(1)Mg10V2 cuboctahedra, faces with two equivalent Mg(7)Mg11V cuboctahedra, faces with four equivalent Mg(5)Mg10VCu cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with four equivalent Mg(3)Mg8V2Cu2 cuboctahedra. In the sixth Mg site, Mg(6) is bonded in a distorted single-bond geometry to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(7), four equivalent Mg(5), and one Cu(1) atom. In the seventh Mg site, Mg(7) is bonded to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(6), four equivalent Mg(5), and one V(1) atom to form distorted MgMg11V cuboctahedra that share corners with six equivalent Mg(7)Mg11V cuboctahedra, corners with eight equivalent Mg(5)Mg10VCu cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent V(1)Mg10Cu2 cuboctahedra, edges with four equivalent Mg(5)Mg10VCu cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(3)Mg8V2Cu2 cuboctahedra,  a faceface with one Mg(2)Mg12 cuboctahedra,  a faceface with one V(1)Mg10Cu2 cuboctahedra, faces with two equivalent Mg(7)Mg11V cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Mg8V2Cu2 cuboctahedra, faces with three equivalent Mg(1)Mg12 cuboctahedra, faces with three equivalent Cu(1)Mg10V2 cuboctahedra, and faces with four equivalent Mg(5)Mg10VCu cuboctahedra. V(1) is bonded to two equivalent Mg(7), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Cu(1) atoms to form VMg10Cu2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent V(1)Mg10Cu2 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Cu(1)Mg10V2 cuboctahedra, edges with four equivalent Mg(7)Mg11V cuboctahedra, edges with four equivalent Mg(3)Mg8V2Cu2 cuboctahedra, edges with eight equivalent Mg(5)Mg10VCu cuboctahedra, faces with two equivalent Mg(7)Mg11V cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Cu(1)Mg10V2 cuboctahedra, faces with four equivalent Mg(5)Mg10VCu cuboctahedra, and faces with four equivalent Mg(3)Mg8V2Cu2 cuboctahedra. Cu(1) is bonded to two equivalent Mg(6), four equivalent Mg(3), four equivalent Mg(5), and two equivalent V(1) atoms to form CuMg10V2 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with six equivalent Cu(1)Mg10V2 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent V(1)Mg10Cu2 cuboctahedra, edges with four equivalent Mg(3)Mg8V2Cu2 cuboctahedra, edges with eight equivalent Mg(5)Mg10VCu cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent V(1)Mg10Cu2 cuboctahedra, faces with four equivalent Mg(5)Mg10VCu cuboctahedra, faces with four equivalent Mg(3)Mg8V2Cu2 cuboctahedra, and faces with six equivalent Mg(7)Mg11V cuboctahedra.
Mg14VCu crystallizes in the orthorhombic Amm2 space group. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2), two equivalent Mg(6), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent V(1)Mg10Cu2 cuboctahedra, corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Mg8V2Cu2 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(5)Mg10VCu cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Cu(1)Mg10V2 cuboctahedra, faces with four equivalent Mg(5)Mg10VCu cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with six equivalent Mg(7)Mg11V cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.14 Å. Both Mg(1)-Mg(6) bond lengths are 3.14 Å. There are two shorter (3.11 Å) and two longer (3.15 Å) Mg(1)-Mg(4) bond lengths. All Mg(1)-Mg(5) bond lengths are 3.19 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(7), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Cu(1)Mg10V2 cuboctahedra, corners with six equivalent Mg(2)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Mg8V2Cu2 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(7)Mg11V cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(5)Mg10VCu cuboctahedra, faces with two equivalent Mg(7)Mg11V cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent V(1)Mg10Cu2 cuboctahedra, faces with four equivalent Mg(5)Mg10VCu cuboctahedra, and faces with four equivalent Mg(4)Mg12 cuboctahedra. Both Mg(2)-Mg(7) bond lengths are 3.09 Å. There are two shorter (3.10 Å) and two longer (3.16 Å) Mg(2)-Mg(4) bond lengths. All Mg(2)-Mg(5) bond lengths are 3.19 Å. In the third Mg site, Mg(3) is bonded to two equivalent Mg(3), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), two equivalent V(1), and two equivalent Cu(1) atoms to form distorted MgMg8V2Cu2 cuboctahedra that share 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 six equivalent Mg(3)Mg8V2Cu2 cuboctahedra, edges with two equivalent Mg(3)Mg8V2Cu2 cuboctahedra, edges with two equivalent V(1)Mg10Cu2 cuboctahedra, edges with two equivalent Cu(1)Mg10V2 cuboctahedra, edges with four equivalent Mg(5)Mg10VCu cuboctahedra, edges with four equivalent Mg(7)Mg11V cuboctahedra, faces with two equivalent Mg(7)Mg11V cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Mg8V2Cu2 cuboctahedra, faces with two equivalent V(1)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10V2 cuboctahedra, and faces with eight equivalent Mg(5)Mg10VCu cuboctahedra. There is one shorter (3.08 Å) and one longer (3.20 Å) Mg(3)-Mg(3) bond length. Both Mg(3)-Mg(5) bond lengths are 3.00 Å. Both Mg(3)-Mg(6) bond lengths are 3.03 Å. Both Mg(3)-Mg(7) bond lengths are 3.05 Å. There is one shorter (3.08 Å) and one longer (3.18 Å) Mg(3)-V(1) bond length. There is one shorter (3.12 Å) and one longer (3.14 Å) Mg(3)-Cu(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)Mg8V2Cu2 cuboctahedra, corners with four equivalent V(1)Mg10Cu2 cuboctahedra, corners with four equivalent Cu(1)Mg10V2 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)Mg10VCu cuboctahedra, edges with four equivalent Mg(7)Mg11V cuboctahedra, faces with two equivalent Mg(7)Mg11V 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)Mg8V2Cu2 cuboctahedra, and faces with eight equivalent Mg(5)Mg10VCu cuboctahedra. There is one shorter (3.13 Å) and one longer (3.14 Å) Mg(4)-Mg(4) bond length. Both Mg(4)-Mg(5) bond lengths are 3.22 Å. Both Mg(4)-Mg(6) bond lengths are 3.17 Å. Both Mg(4)-Mg(7) bond lengths are 3.12 Å. In the fifth 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 V(1), and one Cu(1) atom to form distorted MgMg10VCu cuboctahedra that share corners with four equivalent Mg(7)Mg11V cuboctahedra, corners with ten equivalent Mg(5)Mg10VCu cuboctahedra, edges with two equivalent Mg(5)Mg10VCu cuboctahedra, edges with two equivalent Mg(7)Mg11V 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)Mg8V2Cu2 cuboctahedra, edges with two equivalent V(1)Mg10Cu2 cuboctahedra, edges with two equivalent Cu(1)Mg10V2 cuboctahedra,  a faceface with one Mg(1)Mg12 cuboctahedra,  a faceface with one Mg(2)Mg12 cuboctahedra,  a faceface with one V(1)Mg10Cu2 cuboctahedra,  a faceface with one Cu(1)Mg10V2 cuboctahedra, faces with two equivalent Mg(7)Mg11V cuboctahedra, faces with four equivalent Mg(5)Mg10VCu cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with four equivalent Mg(3)Mg8V2Cu2 cuboctahedra. There is one shorter (3.12 Å) and one longer (3.15 Å) Mg(5)-Mg(5) bond length. There is one shorter (3.06 Å) and one longer (3.20 Å) Mg(5)-Mg(6) bond length. There is one shorter (3.07 Å) and one longer (3.20 Å) Mg(5)-Mg(7) bond length. The Mg(5)-V(1) bond length is 2.97 Å. The Mg(5)-Cu(1) bond length is 2.95 Å. In the sixth Mg site, Mg(6) is bonded in a distorted single-bond geometry to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(7), four equivalent Mg(5), and one Cu(1) atom. Both Mg(6)-Mg(7) bond lengths are 3.14 Å. The Mg(6)-Cu(1) bond length is 2.99 Å. In the seventh Mg site, Mg(7) is bonded to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(6), four equivalent Mg(5), and one V(1) atom to form distorted MgMg11V cuboctahedra that share corners with six equivalent Mg(7)Mg11V cuboctahedra, corners with eight equivalent Mg(5)Mg10VCu cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent V(1)Mg10Cu2 cuboctahedra, edges with four equivalent Mg(5)Mg10VCu cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(3)Mg8V2Cu2 cuboctahedra,  a faceface with one Mg(2)Mg12 cuboctahedra,  a faceface with one V(1)Mg10Cu2 cuboctahedra, faces with two equivalent Mg(7)Mg11V cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Mg8V2Cu2 cuboctahedra, faces with three equivalent Mg(1)Mg12 cuboctahedra, faces with three equivalent Cu(1)Mg10V2 cuboctahedra, and faces with four equivalent Mg(5)Mg10VCu cuboctahedra. The Mg(7)-V(1) bond length is 3.03 Å. V(1) is bonded to two equivalent Mg(7), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Cu(1) atoms to form VMg10Cu2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent V(1)Mg10Cu2 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Cu(1)Mg10V2 cuboctahedra, edges with four equivalent Mg(7)Mg11V cuboctahedra, edges with four equivalent Mg(3)Mg8V2Cu2 cuboctahedra, edges with eight equivalent Mg(5)Mg10VCu cuboctahedra, faces with two equivalent Mg(7)Mg11V cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Cu(1)Mg10V2 cuboctahedra, faces with four equivalent Mg(5)Mg10VCu cuboctahedra, and faces with four equivalent Mg(3)Mg8V2Cu2 cuboctahedra. Both V(1)-Cu(1) bond lengths are 3.14 Å. Cu(1) is bonded to two equivalent Mg(6), four equivalent Mg(3), four equivalent Mg(5), and two equivalent V(1) atoms to form CuMg10V2 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with six equivalent Cu(1)Mg10V2 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent V(1)Mg10Cu2 cuboctahedra, edges with four equivalent Mg(3)Mg8V2Cu2 cuboctahedra, edges with eight equivalent Mg(5)Mg10VCu cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent V(1)Mg10Cu2 cuboctahedra, faces with four equivalent Mg(5)Mg10VCu cuboctahedra, faces with four equivalent Mg(3)Mg8V2Cu2 cuboctahedra, and faces with six equivalent Mg(7)Mg11V cuboctahedra.