YMg4Cu crystallizes in the orthorhombic Cmmm space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 11-coordinate geometry to one Mg(5), two equivalent Mg(2), four equivalent Mg(3), and four equivalent Mg(4) atoms. In the second Mg site, Mg(2) is bonded in a distorted water-like geometry to one Mg(1) and two equivalent Cu(1) atoms. In the third Mg site, Mg(3) is bonded in a distorted single-bond geometry to two equivalent Mg(1), two equivalent Mg(5), and one Cu(1) atom. In the fourth Mg site, Mg(4) is bonded in a distorted single-bond geometry to two equivalent Mg(1) and one Cu(1) atom. In the fifth Mg site, Mg(5) is bonded in a 10-coordinate geometry to two equivalent Mg(1) and eight equivalent Mg(3) atoms. In the sixth Mg site, Mg(6) is bonded in a distorted square co-planar geometry to four equivalent Cu(1) atoms. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 4-coordinate geometry to four equivalent Cu(1) atoms. In the second Y site, Y(2) is bonded in a 4-coordinate geometry to four equivalent Cu(1) atoms. Cu(1) is bonded in a 9-coordinate geometry to one Mg(3), one Mg(4), one Mg(6), two equivalent Mg(2), two equivalent Y(1), and two equivalent Y(2) atoms.
YMg4Cu crystallizes in the orthorhombic Cmmm space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 11-coordinate geometry to one Mg(5), two equivalent Mg(2), four equivalent Mg(3), and four equivalent Mg(4) atoms. The Mg(1)-Mg(5) bond length is 3.28 Å. Both Mg(1)-Mg(2) bond lengths are 3.25 Å. All Mg(1)-Mg(3) bond lengths are 3.15 Å. All Mg(1)-Mg(4) bond lengths are 3.14 Å. In the second Mg site, Mg(2) is bonded in a distorted water-like geometry to one Mg(1) and two equivalent Cu(1) atoms. Both Mg(2)-Cu(1) bond lengths are 2.69 Å. In the third Mg site, Mg(3) is bonded in a distorted single-bond geometry to two equivalent Mg(1), two equivalent Mg(5), and one Cu(1) atom. Both Mg(3)-Mg(5) bond lengths are 3.11 Å. The Mg(3)-Cu(1) bond length is 2.83 Å. In the fourth Mg site, Mg(4) is bonded in a distorted single-bond geometry to two equivalent Mg(1) and one Cu(1) atom. The Mg(4)-Cu(1) bond length is 2.83 Å. In the fifth Mg site, Mg(5) is bonded in a 10-coordinate geometry to two equivalent Mg(1) and eight equivalent Mg(3) atoms. In the sixth Mg site, Mg(6) is bonded in a distorted square co-planar geometry to four equivalent Cu(1) atoms. All Mg(6)-Cu(1) bond lengths are 2.98 Å. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 4-coordinate geometry to four equivalent Cu(1) atoms. All Y(1)-Cu(1) bond lengths are 2.96 Å. In the second Y site, Y(2) is bonded in a 4-coordinate geometry to four equivalent Cu(1) atoms. All Y(2)-Cu(1) bond lengths are 2.97 Å. Cu(1) is bonded in a 9-coordinate geometry to one Mg(3), one Mg(4), one Mg(6), two equivalent Mg(2), two equivalent Y(1), and two equivalent Y(2) atoms.