Mg6WCu 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 W(1), and two equivalent Cu(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 Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent Cu(1)Mg10W2 cuboctahedra, corners with six equivalent Mg(2)Mg10Cu2 cuboctahedra, edges with two equivalent Cu(1)Mg10W2 cuboctahedra, faces with two equivalent Mg(2)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10W2 cuboctahedra, and faces with six equivalent W(1)Mg10Cu2 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent Mg(2), two equivalent W(1), and two equivalent Cu(1) atoms. In the fourth Mg site, Mg(4) is bonded in a distorted linear geometry to two equivalent Mg(2) and two equivalent W(1) atoms. W(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Cu(1) atoms to form WMg10Cu2 cuboctahedra that share corners with six equivalent W(1)Mg10Cu2 cuboctahedra, edges with four equivalent Cu(1)Mg10W2 cuboctahedra, faces with two equivalent W(1)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10W2 cuboctahedra, and faces with six equivalent Mg(2)Mg10Cu2 cuboctahedra. Cu(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent W(1) atoms to form distorted CuMg10W2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Cu2 cuboctahedra, corners with six equivalent Cu(1)Mg10W2 cuboctahedra, edges with two equivalent Mg(2)Mg10Cu2 cuboctahedra, edges with four equivalent W(1)Mg10Cu2 cuboctahedra, faces with two equivalent Mg(2)Mg10Cu2 cuboctahedra, faces with two equivalent W(1)Mg10Cu2 cuboctahedra, and faces with two equivalent Cu(1)Mg10W2 cuboctahedra.
Mg6WCu 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 W(1), and two equivalent Cu(1) atoms. There is one shorter (3.00 Å) and one longer (3.05 Å) Mg(1)-Mg(2) bond length. Both Mg(1)-W(1) bond lengths are 2.91 Å. There is one shorter (2.75 Å) and one longer (3.30 Å) Mg(1)-Cu(1) bond length. 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 Cu(1) atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent Cu(1)Mg10W2 cuboctahedra, corners with six equivalent Mg(2)Mg10Cu2 cuboctahedra, edges with two equivalent Cu(1)Mg10W2 cuboctahedra, faces with two equivalent Mg(2)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10W2 cuboctahedra, and faces with six equivalent W(1)Mg10Cu2 cuboctahedra. Both Mg(2)-Mg(4) bond lengths are 2.97 Å. All Mg(2)-Mg(3) bond lengths are 2.99 Å. Both Mg(2)-Cu(1) bond lengths are 3.00 Å. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent Mg(2), two equivalent W(1), and two equivalent Cu(1) atoms. There is one shorter (2.93 Å) and one longer (3.11 Å) Mg(3)-W(1) bond length. Both Mg(3)-Cu(1) bond lengths are 2.99 Å. In the fourth Mg site, Mg(4) is bonded in a distorted linear geometry to two equivalent Mg(2) and two equivalent W(1) atoms. Both Mg(4)-W(1) bond lengths are 3.00 Å. W(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Cu(1) atoms to form WMg10Cu2 cuboctahedra that share corners with six equivalent W(1)Mg10Cu2 cuboctahedra, edges with four equivalent Cu(1)Mg10W2 cuboctahedra, faces with two equivalent W(1)Mg10Cu2 cuboctahedra, faces with two equivalent Cu(1)Mg10W2 cuboctahedra, and faces with six equivalent Mg(2)Mg10Cu2 cuboctahedra. Both W(1)-Cu(1) bond lengths are 2.82 Å. Cu(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent W(1) atoms to form distorted CuMg10W2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Cu2 cuboctahedra, corners with six equivalent Cu(1)Mg10W2 cuboctahedra, edges with two equivalent Mg(2)Mg10Cu2 cuboctahedra, edges with four equivalent W(1)Mg10Cu2 cuboctahedra, faces with two equivalent Mg(2)Mg10Cu2 cuboctahedra, faces with two equivalent W(1)Mg10Cu2 cuboctahedra, and faces with two equivalent Cu(1)Mg10W2 cuboctahedra.