Ni7Tb2 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 12-coordinate geometry to three equivalent Ni(1) and nine equivalent Ni(3) atoms. In the second Tb site, Tb(2) is bonded in a 18-coordinate geometry to three equivalent Ni(4), three equivalent Ni(5), six equivalent Ni(2), and six equivalent Ni(3) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(5) is bonded in a 9-coordinate geometry to three equivalent Tb(2), three equivalent Ni(2), and three equivalent Ni(3) atoms. In the second Ni site, Ni(1) is bonded to six equivalent Tb(1) and six equivalent Ni(3) atoms to form NiTb6Ni6 cuboctahedra that share corners with twelve equivalent Ni(3)Tb5Ni7 cuboctahedra, edges with six equivalent Ni(1)Tb6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(3)Tb5Ni7 cuboctahedra. In the third Ni site, Ni(2) is bonded to four equivalent Tb(2), two equivalent Ni(4), two equivalent Ni(5), and four equivalent Ni(2) atoms to form NiTb4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Tb4Ni8 cuboctahedra, corners with twelve equivalent Ni(3)Tb5Ni7 cuboctahedra, edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra, edges with eight equivalent Ni(3)Tb5Ni7 cuboctahedra, faces with two equivalent Ni(3)Tb5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Tb4Ni8 cuboctahedra. In the fourth Ni site, Ni(3) is bonded to two equivalent Tb(2), three equivalent Tb(1), one Ni(1), one Ni(4), one Ni(5), and four equivalent Ni(3) atoms to form distorted NiTb5Ni7 cuboctahedra that share corners with two equivalent Ni(1)Tb6Ni6 cuboctahedra, corners with six equivalent Ni(2)Tb4Ni8 cuboctahedra, corners with nine equivalent Ni(3)Tb5Ni7 cuboctahedra, edges with four equivalent Ni(2)Tb4Ni8 cuboctahedra, edges with four equivalent Ni(3)Tb5Ni7 cuboctahedra,  a faceface with one Ni(2)Tb4Ni8 cuboctahedra, faces with three equivalent Ni(1)Tb6Ni6 cuboctahedra, and faces with ten equivalent Ni(3)Tb5Ni7 cuboctahedra. In the fifth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Tb(2), three equivalent Ni(2), and three equivalent Ni(3) atoms.
Ni7Tb2 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 12-coordinate geometry to three equivalent Ni(1) and nine equivalent Ni(3) atoms. All Tb(1)-Ni(1) bond lengths are 2.93 Å. There are six shorter (2.81 Å) and three longer (3.13 Å) Tb(1)-Ni(3) bond lengths. In the second Tb site, Tb(2) is bonded in a 18-coordinate geometry to three equivalent Ni(4), three equivalent Ni(5), six equivalent Ni(2), and six equivalent Ni(3) atoms. All Tb(2)-Ni(4) bond lengths are 2.85 Å. All Tb(2)-Ni(5) bond lengths are 2.85 Å. All Tb(2)-Ni(2) bond lengths are 3.07 Å. All Tb(2)-Ni(3) bond lengths are 3.25 Å. There are five inequivalent Ni sites. In the first Ni site, Ni(5) is bonded in a 9-coordinate geometry to three equivalent Tb(2), three equivalent Ni(2), and three equivalent Ni(3) atoms. All Ni(5)-Ni(2) bond lengths are 2.44 Å. All Ni(5)-Ni(3) bond lengths are 2.42 Å. In the second Ni site, Ni(1) is bonded to six equivalent Tb(1) and six equivalent Ni(3) atoms to form NiTb6Ni6 cuboctahedra that share corners with twelve equivalent Ni(3)Tb5Ni7 cuboctahedra, edges with six equivalent Ni(1)Tb6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(3)Tb5Ni7 cuboctahedra. All Ni(1)-Ni(3) bond lengths are 2.52 Å. In the third Ni site, Ni(2) is bonded to four equivalent Tb(2), two equivalent Ni(4), two equivalent Ni(5), and four equivalent Ni(2) atoms to form NiTb4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Tb4Ni8 cuboctahedra, corners with twelve equivalent Ni(3)Tb5Ni7 cuboctahedra, edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra, edges with eight equivalent Ni(3)Tb5Ni7 cuboctahedra, faces with two equivalent Ni(3)Tb5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Tb4Ni8 cuboctahedra. Both Ni(2)-Ni(4) bond lengths are 2.43 Å. There are two shorter (2.46 Å) and two longer (2.47 Å) Ni(2)-Ni(2) bond lengths. In the fourth Ni site, Ni(3) is bonded to two equivalent Tb(2), three equivalent Tb(1), one Ni(1), one Ni(4), one Ni(5), and four equivalent Ni(3) atoms to form distorted NiTb5Ni7 cuboctahedra that share corners with two equivalent Ni(1)Tb6Ni6 cuboctahedra, corners with six equivalent Ni(2)Tb4Ni8 cuboctahedra, corners with nine equivalent Ni(3)Tb5Ni7 cuboctahedra, edges with four equivalent Ni(2)Tb4Ni8 cuboctahedra, edges with four equivalent Ni(3)Tb5Ni7 cuboctahedra,  a faceface with one Ni(2)Tb4Ni8 cuboctahedra, faces with three equivalent Ni(1)Tb6Ni6 cuboctahedra, and faces with ten equivalent Ni(3)Tb5Ni7 cuboctahedra. The Ni(3)-Ni(4) bond length is 2.44 Å. All Ni(3)-Ni(3) bond lengths are 2.46 Å. In the fifth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Tb(2), three equivalent Ni(2), and three equivalent Ni(3) atoms.