Dy2Ni7 crystallizes in the monoclinic C2/m space group. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 18-coordinate geometry to two equivalent Ni(2), two equivalent Ni(6), three equivalent Ni(3), three equivalent Ni(4), four equivalent Ni(1), and four equivalent Ni(5) atoms. In the second Dy site, Dy(2) is bonded in a 12-coordinate geometry to three equivalent Ni(6), three equivalent Ni(7), and six equivalent Ni(5) atoms. There are seven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Dy(1), two equivalent Ni(1), two equivalent Ni(2), two equivalent Ni(3), and two equivalent Ni(4) atoms to form NiDy4Ni8 cuboctahedra that share corners with four equivalent Ni(1)Dy4Ni8 cuboctahedra, corners with four equivalent Ni(6)Dy5Ni7 cuboctahedra, corners with eight equivalent Ni(5)Dy5Ni7 cuboctahedra, edges with two equivalent Ni(1)Dy4Ni8 cuboctahedra, edges with four equivalent Ni(5)Dy5Ni7 cuboctahedra, edges with four equivalent Ni(6)Dy5Ni7 cuboctahedra, faces with two equivalent Ni(5)Dy5Ni7 cuboctahedra, faces with four equivalent Ni(1)Dy4Ni8 cuboctahedra, and faces with four equivalent Ni(2)Dy4Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to four equivalent Dy(1), two equivalent Ni(3), two equivalent Ni(4), and four equivalent Ni(1) atoms to form NiDy4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Dy4Ni8 cuboctahedra, corners with four equivalent Ni(6)Dy5Ni7 cuboctahedra, corners with eight equivalent Ni(5)Dy5Ni7 cuboctahedra, edges with two equivalent Ni(2)Dy4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Dy5Ni7 cuboctahedra, faces with two equivalent Ni(6)Dy5Ni7 cuboctahedra, and faces with eight equivalent Ni(1)Dy4Ni8 cuboctahedra. In the third Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Dy(1), one Ni(2), one Ni(6), two equivalent Ni(1), and two equivalent Ni(5) atoms. In the fourth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Dy(1), one Ni(2), one Ni(6), two equivalent Ni(1), and two equivalent Ni(5) atoms. In the fifth Ni site, Ni(5) is bonded to two equivalent Dy(1), three equivalent Dy(2), one Ni(3), one Ni(4), one Ni(7), two equivalent Ni(5), and two equivalent Ni(6) atoms to form distorted NiDy5Ni7 cuboctahedra that share corners with two equivalent Ni(2)Dy4Ni8 cuboctahedra, corners with two equivalent Ni(6)Dy5Ni7 cuboctahedra, corners with two equivalent Ni(7)Dy6Ni6 cuboctahedra, corners with four equivalent Ni(1)Dy4Ni8 cuboctahedra, corners with seven equivalent Ni(5)Dy5Ni7 cuboctahedra, edges with two equivalent Ni(1)Dy4Ni8 cuboctahedra, edges with two equivalent Ni(2)Dy4Ni8 cuboctahedra, edges with four equivalent Ni(5)Dy5Ni7 cuboctahedra,  a faceface with one Ni(1)Dy4Ni8 cuboctahedra, faces with three equivalent Ni(7)Dy6Ni6 cuboctahedra, faces with five equivalent Ni(5)Dy5Ni7 cuboctahedra, and faces with five equivalent Ni(6)Dy5Ni7 cuboctahedra. In the sixth Ni site, Ni(6) is bonded to two equivalent Dy(1), three equivalent Dy(2), one Ni(3), one Ni(4), one Ni(7), and four equivalent Ni(5) atoms to form distorted NiDy5Ni7 cuboctahedra that share corners with two equivalent Ni(2)Dy4Ni8 cuboctahedra, corners with two equivalent Ni(7)Dy6Ni6 cuboctahedra, corners with four equivalent Ni(1)Dy4Ni8 cuboctahedra, corners with four equivalent Ni(5)Dy5Ni7 cuboctahedra, corners with five equivalent Ni(6)Dy5Ni7 cuboctahedra, edges with four equivalent Ni(1)Dy4Ni8 cuboctahedra, edges with four equivalent Ni(6)Dy5Ni7 cuboctahedra,  a faceface with one Ni(2)Dy4Ni8 cuboctahedra, faces with three equivalent Ni(7)Dy6Ni6 cuboctahedra, and faces with ten equivalent Ni(5)Dy5Ni7 cuboctahedra. In the seventh Ni site, Ni(7) is bonded to six equivalent Dy(2), two equivalent Ni(6), and four equivalent Ni(5) atoms to form NiDy6Ni6 cuboctahedra that share corners with four equivalent Ni(6)Dy5Ni7 cuboctahedra, corners with eight equivalent Ni(5)Dy5Ni7 cuboctahedra, edges with six equivalent Ni(7)Dy6Ni6 cuboctahedra, faces with six equivalent Ni(6)Dy5Ni7 cuboctahedra, and faces with twelve equivalent Ni(5)Dy5Ni7 cuboctahedra.
Dy2Ni7 crystallizes in the monoclinic C2/m space group. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 18-coordinate geometry to two equivalent Ni(2), two equivalent Ni(6), three equivalent Ni(3), three equivalent Ni(4), four equivalent Ni(1), and four equivalent Ni(5) atoms. Both Dy(1)-Ni(2) bond lengths are 3.02 Å. Both Dy(1)-Ni(6) bond lengths are 3.20 Å. There are two shorter (2.80 Å) and one longer (2.81 Å) Dy(1)-Ni(3) bond length. There is one shorter (2.80 Å) and two longer (2.81 Å) Dy(1)-Ni(4) bond lengths. There are two shorter (3.01 Å) and two longer (3.03 Å) Dy(1)-Ni(1) bond lengths. There are two shorter (3.20 Å) and two longer (3.21 Å) Dy(1)-Ni(5) bond lengths. In the second Dy site, Dy(2) is bonded in a 12-coordinate geometry to three equivalent Ni(6), three equivalent Ni(7), and six equivalent Ni(5) atoms. There are two shorter (2.77 Å) and one longer (3.08 Å) Dy(2)-Ni(6) bond length. All Dy(2)-Ni(7) bond lengths are 2.89 Å. There are four shorter (2.77 Å) and two longer (3.08 Å) Dy(2)-Ni(5) bond lengths. There are seven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Dy(1), two equivalent Ni(1), two equivalent Ni(2), two equivalent Ni(3), and two equivalent Ni(4) atoms to form NiDy4Ni8 cuboctahedra that share corners with four equivalent Ni(1)Dy4Ni8 cuboctahedra, corners with four equivalent Ni(6)Dy5Ni7 cuboctahedra, corners with eight equivalent Ni(5)Dy5Ni7 cuboctahedra, edges with two equivalent Ni(1)Dy4Ni8 cuboctahedra, edges with four equivalent Ni(5)Dy5Ni7 cuboctahedra, edges with four equivalent Ni(6)Dy5Ni7 cuboctahedra, faces with two equivalent Ni(5)Dy5Ni7 cuboctahedra, faces with four equivalent Ni(1)Dy4Ni8 cuboctahedra, and faces with four equivalent Ni(2)Dy4Ni8 cuboctahedra. Both Ni(1)-Ni(1) bond lengths are 2.43 Å. Both Ni(1)-Ni(2) bond lengths are 2.42 Å. Both Ni(1)-Ni(3) bond lengths are 2.41 Å. Both Ni(1)-Ni(4) bond lengths are 2.40 Å. In the second Ni site, Ni(2) is bonded to four equivalent Dy(1), two equivalent Ni(3), two equivalent Ni(4), and four equivalent Ni(1) atoms to form NiDy4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Dy4Ni8 cuboctahedra, corners with four equivalent Ni(6)Dy5Ni7 cuboctahedra, corners with eight equivalent Ni(5)Dy5Ni7 cuboctahedra, edges with two equivalent Ni(2)Dy4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Dy5Ni7 cuboctahedra, faces with two equivalent Ni(6)Dy5Ni7 cuboctahedra, and faces with eight equivalent Ni(1)Dy4Ni8 cuboctahedra. Both Ni(2)-Ni(3) bond lengths are 2.39 Å. Both Ni(2)-Ni(4) bond lengths are 2.41 Å. In the third Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Dy(1), one Ni(2), one Ni(6), two equivalent Ni(1), and two equivalent Ni(5) atoms. The Ni(3)-Ni(6) bond length is 2.39 Å. Both Ni(3)-Ni(5) bond lengths are 2.40 Å. In the fourth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Dy(1), one Ni(2), one Ni(6), two equivalent Ni(1), and two equivalent Ni(5) atoms. The Ni(4)-Ni(6) bond length is 2.39 Å. Both Ni(4)-Ni(5) bond lengths are 2.38 Å. In the fifth Ni site, Ni(5) is bonded to two equivalent Dy(1), three equivalent Dy(2), one Ni(3), one Ni(4), one Ni(7), two equivalent Ni(5), and two equivalent Ni(6) atoms to form distorted NiDy5Ni7 cuboctahedra that share corners with two equivalent Ni(2)Dy4Ni8 cuboctahedra, corners with two equivalent Ni(6)Dy5Ni7 cuboctahedra, corners with two equivalent Ni(7)Dy6Ni6 cuboctahedra, corners with four equivalent Ni(1)Dy4Ni8 cuboctahedra, corners with seven equivalent Ni(5)Dy5Ni7 cuboctahedra, edges with two equivalent Ni(1)Dy4Ni8 cuboctahedra, edges with two equivalent Ni(2)Dy4Ni8 cuboctahedra, edges with four equivalent Ni(5)Dy5Ni7 cuboctahedra,  a faceface with one Ni(1)Dy4Ni8 cuboctahedra, faces with three equivalent Ni(7)Dy6Ni6 cuboctahedra, faces with five equivalent Ni(5)Dy5Ni7 cuboctahedra, and faces with five equivalent Ni(6)Dy5Ni7 cuboctahedra. The Ni(5)-Ni(7) bond length is 2.48 Å. There is one shorter (2.42 Å) and one longer (2.43 Å) Ni(5)-Ni(5) bond length. There is one shorter (2.42 Å) and one longer (2.43 Å) Ni(5)-Ni(6) bond length. In the sixth Ni site, Ni(6) is bonded to two equivalent Dy(1), three equivalent Dy(2), one Ni(3), one Ni(4), one Ni(7), and four equivalent Ni(5) atoms to form distorted NiDy5Ni7 cuboctahedra that share corners with two equivalent Ni(2)Dy4Ni8 cuboctahedra, corners with two equivalent Ni(7)Dy6Ni6 cuboctahedra, corners with four equivalent Ni(1)Dy4Ni8 cuboctahedra, corners with four equivalent Ni(5)Dy5Ni7 cuboctahedra, corners with five equivalent Ni(6)Dy5Ni7 cuboctahedra, edges with four equivalent Ni(1)Dy4Ni8 cuboctahedra, edges with four equivalent Ni(6)Dy5Ni7 cuboctahedra,  a faceface with one Ni(2)Dy4Ni8 cuboctahedra, faces with three equivalent Ni(7)Dy6Ni6 cuboctahedra, and faces with ten equivalent Ni(5)Dy5Ni7 cuboctahedra. The Ni(6)-Ni(7) bond length is 2.48 Å. In the seventh Ni site, Ni(7) is bonded to six equivalent Dy(2), two equivalent Ni(6), and four equivalent Ni(5) atoms to form NiDy6Ni6 cuboctahedra that share corners with four equivalent Ni(6)Dy5Ni7 cuboctahedra, corners with eight equivalent Ni(5)Dy5Ni7 cuboctahedra, edges with six equivalent Ni(7)Dy6Ni6 cuboctahedra, faces with six equivalent Ni(6)Dy5Ni7 cuboctahedra, and faces with twelve equivalent Ni(5)Dy5Ni7 cuboctahedra.