Ni7Tb2 crystallizes in the trigonal R-3m space group. There are six inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2) atoms. In the second Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3), three equivalent Ni(4), six equivalent Ni(1), and six equivalent Ni(2) atoms. In the third Tb site, Tb(2) is bonded in a 12-coordinate geometry to three equivalent Ni(5) and nine equivalent Ni(1) atoms. In the fourth Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2,2) atoms. In the fifth Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2) atoms. In the sixth Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2,2) atoms. There are seven inequivalent Ni sites. In the first Ni site, Ni(2) is bonded to four Tb(1,1); two equivalent Ni(3); two equivalent Ni(4); and four Ni(2,2) atoms to form NiTb4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Tb4Ni8 cuboctahedra; corners with twelve equivalent Ni(1)Tb5Ni7 cuboctahedra; edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra; edges with eight equivalent Ni(1)Tb5Ni7 cuboctahedra; faces with two equivalent Ni(1)Tb5Ni7 cuboctahedra; and faces with eight Ni(2,2)Tb4Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to four Tb(1,1); two equivalent Ni(3); two equivalent Ni(4); 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(1)Tb5Ni7 cuboctahedra, edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra, edges with eight equivalent Ni(1)Tb5Ni7 cuboctahedra, faces with two equivalent Ni(1)Tb5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Tb4Ni8 cuboctahedra. In the third Ni site, Ni(1) is bonded to two equivalent Tb(1), three equivalent Tb(2), one Ni(3), one Ni(4), one Ni(5), and four equivalent Ni(1) atoms to form distorted NiTb5Ni7 cuboctahedra that share corners with two equivalent Ni(5)Tb6Ni6 cuboctahedra; corners with six Ni(2,2)Tb4Ni8 cuboctahedra; corners with nine equivalent Ni(1)Tb5Ni7 cuboctahedra; edges with four equivalent Ni(2)Tb4Ni8 cuboctahedra; edges with four equivalent Ni(1)Tb5Ni7 cuboctahedra;  a faceface with one Ni(2)Tb4Ni8 cuboctahedra; faces with three equivalent Ni(5)Tb6Ni6 cuboctahedra; and faces with ten equivalent Ni(1)Tb5Ni7 cuboctahedra. In the fourth Ni site, Ni(2) is bonded to four equivalent Tb(1), two equivalent Ni(3), two equivalent Ni(4), 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(1)Tb5Ni7 cuboctahedra, edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra, edges with eight equivalent Ni(1)Tb5Ni7 cuboctahedra, faces with two equivalent Ni(1)Tb5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Tb4Ni8 cuboctahedra. In the fifth Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Tb(1), three equivalent Ni(1), and three equivalent Ni(2) atoms. In the sixth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Tb(1); three equivalent Ni(1); and three Ni(2,2) atoms. In the seventh Ni site, Ni(5) is bonded to six equivalent Tb(2) and six equivalent Ni(1) atoms to form NiTb6Ni6 cuboctahedra that share corners with twelve equivalent Ni(1)Tb5Ni7 cuboctahedra, edges with six equivalent Ni(5)Tb6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)Tb5Ni7 cuboctahedra.
Ni7Tb2 crystallizes in the trigonal R-3m space group. There are six inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2) atoms. All Tb(1)-Ni(3) bond lengths are 2.85 Å. All Tb(1)-Ni(4) bond lengths are 2.85 Å. All Tb(1)-Ni(1) bond lengths are 3.25 Å. All Tb(1)-Ni(2,2) bond lengths are 3.07 Å. In the second Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3), three equivalent Ni(4), six equivalent Ni(1), and six equivalent Ni(2) atoms. All Tb(1)-Ni(3) bond lengths are 2.85 Å. All Tb(1)-Ni(4) bond lengths are 2.85 Å. All Tb(1)-Ni(1) bond lengths are 3.25 Å. All Tb(1)-Ni(2) bond lengths are 3.07 Å. In the third Tb site, Tb(2) is bonded in a 12-coordinate geometry to three equivalent Ni(5) and nine equivalent Ni(1) atoms. All Tb(2)-Ni(5) bond lengths are 2.93 Å. There are six shorter (2.82 Å) and three longer (3.08 Å) Tb(2)-Ni(1) bond lengths. In the fourth Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2,2) atoms. All Tb(1)-Ni(3) bond lengths are 2.85 Å. All Tb(1)-Ni(4) bond lengths are 2.85 Å. All Tb(1)-Ni(1) bond lengths are 3.25 Å. All Tb(1)-Ni(2,2,2) bond lengths are 3.07 Å. In the fifth Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2) atoms. All Tb(1)-Ni(3) bond lengths are 2.85 Å. All Tb(1)-Ni(4) bond lengths are 2.85 Å. All Tb(1)-Ni(1) bond lengths are 3.25 Å. All Tb(1)-Ni(2,2) bond lengths are 3.07 Å. In the sixth Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2,2) atoms. All Tb(1)-Ni(3) bond lengths are 2.85 Å. All Tb(1)-Ni(4) bond lengths are 2.85 Å. All Tb(1)-Ni(1) bond lengths are 3.25 Å. All Tb(1)-Ni(2,2,2) bond lengths are 3.07 Å. There are seven inequivalent Ni sites. In the first Ni site, Ni(2) is bonded to four Tb(1,1); two equivalent Ni(3); two equivalent Ni(4); and four Ni(2,2) atoms to form NiTb4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Tb4Ni8 cuboctahedra; corners with twelve equivalent Ni(1)Tb5Ni7 cuboctahedra; edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra; edges with eight equivalent Ni(1)Tb5Ni7 cuboctahedra; faces with two equivalent Ni(1)Tb5Ni7 cuboctahedra; and faces with eight Ni(2,2)Tb4Ni8 cuboctahedra. Both Ni(2)-Ni(3) bond lengths are 2.45 Å. Both Ni(2)-Ni(4) bond lengths are 2.43 Å. All Ni(2)-Ni(2,2) bond lengths are 2.46 Å. In the second Ni site, Ni(2) is bonded to four Tb(1,1); two equivalent Ni(3); two equivalent Ni(4); 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(1)Tb5Ni7 cuboctahedra, edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra, edges with eight equivalent Ni(1)Tb5Ni7 cuboctahedra, faces with two equivalent Ni(1)Tb5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Tb4Ni8 cuboctahedra. Both Ni(2)-Ni(3) bond lengths are 2.45 Å. Both Ni(2)-Ni(4) bond lengths are 2.43 Å. In the third Ni site, Ni(1) is bonded to two equivalent Tb(1), three equivalent Tb(2), one Ni(3), one Ni(4), one Ni(5), and four equivalent Ni(1) atoms to form distorted NiTb5Ni7 cuboctahedra that share corners with two equivalent Ni(5)Tb6Ni6 cuboctahedra; corners with six Ni(2,2)Tb4Ni8 cuboctahedra; corners with nine equivalent Ni(1)Tb5Ni7 cuboctahedra; edges with four equivalent Ni(2)Tb4Ni8 cuboctahedra; edges with four equivalent Ni(1)Tb5Ni7 cuboctahedra;  a faceface with one Ni(2)Tb4Ni8 cuboctahedra; faces with three equivalent Ni(5)Tb6Ni6 cuboctahedra; and faces with ten equivalent Ni(1)Tb5Ni7 cuboctahedra. The Ni(1)-Ni(3) bond length is 2.43 Å. The Ni(1)-Ni(4) bond length is 2.44 Å. The Ni(1)-Ni(5) bond length is 2.49 Å. All Ni(1)-Ni(1) bond lengths are 2.46 Å. In the fourth Ni site, Ni(2) is bonded to four equivalent Tb(1), two equivalent Ni(3), two equivalent Ni(4), 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(1)Tb5Ni7 cuboctahedra, edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra, edges with eight equivalent Ni(1)Tb5Ni7 cuboctahedra, faces with two equivalent Ni(1)Tb5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Tb4Ni8 cuboctahedra. Both Ni(2)-Ni(3) bond lengths are 2.45 Å. Both Ni(2)-Ni(4) bond lengths are 2.43 Å. All Ni(2)-Ni(2) bond lengths are 2.46 Å. In the fifth Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Tb(1), three equivalent Ni(1), and three equivalent Ni(2) atoms. In the sixth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Tb(1); three equivalent Ni(1); and three Ni(2,2) atoms. In the seventh Ni site, Ni(5) is bonded to six equivalent Tb(2) and six equivalent Ni(1) atoms to form NiTb6Ni6 cuboctahedra that share corners with twelve equivalent Ni(1)Tb5Ni7 cuboctahedra, edges with six equivalent Ni(5)Tb6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)Tb5Ni7 cuboctahedra.