Nd2Ni7 crystallizes in the trigonal R-3m space group. There are six inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(2); three equivalent Ni(3); six Ni(4,4); and six equivalent Ni(5) atoms. In the second Nd site, Nd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(2); three equivalent Ni(3); six Ni(4,4); and six equivalent Ni(5) atoms. In the third Nd site, Nd(2) is bonded in a 12-coordinate geometry to three equivalent Ni(1) and nine equivalent Ni(5) atoms. In the fourth Nd site, Nd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(2); three equivalent Ni(3); six Ni(4,4); and six equivalent Ni(5) atoms. In the fifth Nd site, Nd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(2); three equivalent Ni(3); six Ni(4,4); and six equivalent Ni(5) atoms. In the sixth Nd site, Nd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(2); three equivalent Ni(3); six Ni(4,4); and six equivalent Ni(5) atoms. There are eight inequivalent Ni sites. In the first Ni site, Ni(4) is bonded to four Nd(1,1); two equivalent Ni(2); two equivalent Ni(3); and four equivalent Ni(4) atoms to form NiNd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Nd4Ni8 cuboctahedra, corners with twelve equivalent Ni(5)Nd5Ni7 cuboctahedra, edges with two equivalent Ni(4)Nd4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Nd5Ni7 cuboctahedra, faces with two equivalent Ni(5)Nd5Ni7 cuboctahedra, and faces with eight equivalent Ni(4)Nd4Ni8 cuboctahedra. In the second Ni site, Ni(1) is bonded to six equivalent Nd(2) and six equivalent Ni(5) atoms to form NiNd6Ni6 cuboctahedra that share corners with twelve equivalent Ni(5)Nd5Ni7 cuboctahedra, edges with six equivalent Ni(1)Nd6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(5)Nd5Ni7 cuboctahedra. In the third Ni site, Ni(2) is bonded in a 9-coordinate geometry to three equivalent Nd(1); three Ni(4,4); and three equivalent Ni(5) atoms. In the fourth Ni site, Ni(4) is bonded to four Nd(1,1); two equivalent Ni(2); two equivalent Ni(3); and four Ni(4,4) atoms to form NiNd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Nd4Ni8 cuboctahedra; corners with twelve equivalent Ni(5)Nd5Ni7 cuboctahedra; edges with two equivalent Ni(4)Nd4Ni8 cuboctahedra; edges with eight equivalent Ni(5)Nd5Ni7 cuboctahedra; faces with two equivalent Ni(5)Nd5Ni7 cuboctahedra; and faces with eight Ni(4,4)Nd4Ni8 cuboctahedra. In the fifth Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Nd(1); three Ni(4,4); and three equivalent Ni(5) atoms. In the sixth Ni site, Ni(4) is bonded to four Nd(1,1); two equivalent Ni(2); two equivalent Ni(3); and four equivalent Ni(4) atoms to form NiNd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Nd4Ni8 cuboctahedra, corners with twelve equivalent Ni(5)Nd5Ni7 cuboctahedra, edges with two equivalent Ni(4)Nd4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Nd5Ni7 cuboctahedra, faces with two equivalent Ni(5)Nd5Ni7 cuboctahedra, and faces with eight equivalent Ni(4)Nd4Ni8 cuboctahedra. In the seventh Ni site, Ni(4) is bonded to four Nd(1,1); two equivalent Ni(2); two equivalent Ni(3); and four Ni(4,4) atoms to form NiNd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Nd4Ni8 cuboctahedra; corners with twelve equivalent Ni(5)Nd5Ni7 cuboctahedra; edges with two equivalent Ni(4)Nd4Ni8 cuboctahedra; edges with eight equivalent Ni(5)Nd5Ni7 cuboctahedra; faces with two equivalent Ni(5)Nd5Ni7 cuboctahedra; and faces with eight Ni(4,4)Nd4Ni8 cuboctahedra. In the eighth Ni site, Ni(5) is bonded to two equivalent Nd(1), three equivalent Nd(2), one Ni(1), one Ni(2), one Ni(3), and four equivalent Ni(5) atoms to form distorted NiNd5Ni7 cuboctahedra that share corners with two equivalent Ni(1)Nd6Ni6 cuboctahedra; corners with six Ni(4,4)Nd4Ni8 cuboctahedra; corners with nine equivalent Ni(5)Nd5Ni7 cuboctahedra; edges with four Ni(4,4)Nd4Ni8 cuboctahedra; edges with four equivalent Ni(5)Nd5Ni7 cuboctahedra;  a faceface with one Ni(4)Nd4Ni8 cuboctahedra; faces with three equivalent Ni(1)Nd6Ni6 cuboctahedra; and faces with ten equivalent Ni(5)Nd5Ni7 cuboctahedra.
Nd2Ni7 crystallizes in the trigonal R-3m space group. There are six inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(2); three equivalent Ni(3); six Ni(4,4); and six equivalent Ni(5) atoms. All Nd(1)-Ni(2) bond lengths are 2.91 Å. All Nd(1)-Ni(3) bond lengths are 2.91 Å. All Nd(1)-Ni(4,4) bond lengths are 3.12 Å. All Nd(1)-Ni(5) bond lengths are 3.30 Å. In the second Nd site, Nd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(2); three equivalent Ni(3); six Ni(4,4); and six equivalent Ni(5) atoms. All Nd(1)-Ni(2) bond lengths are 2.91 Å. All Nd(1)-Ni(3) bond lengths are 2.91 Å. All Nd(1)-Ni(4,4) bond lengths are 3.12 Å. All Nd(1)-Ni(5) bond lengths are 3.30 Å. In the third Nd site, Nd(2) is bonded in a 12-coordinate geometry to three equivalent Ni(1) and nine equivalent Ni(5) atoms. All Nd(2)-Ni(1) bond lengths are 2.99 Å. There are six shorter (2.89 Å) and three longer (3.18 Å) Nd(2)-Ni(5) bond lengths. In the fourth Nd site, Nd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(2); three equivalent Ni(3); six Ni(4,4); and six equivalent Ni(5) atoms. All Nd(1)-Ni(2) bond lengths are 2.91 Å. All Nd(1)-Ni(3) bond lengths are 2.91 Å. All Nd(1)-Ni(4,4) bond lengths are 3.12 Å. All Nd(1)-Ni(5) bond lengths are 3.30 Å. In the fifth Nd site, Nd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(2); three equivalent Ni(3); six Ni(4,4); and six equivalent Ni(5) atoms. All Nd(1)-Ni(2) bond lengths are 2.91 Å. All Nd(1)-Ni(3) bond lengths are 2.91 Å. All Nd(1)-Ni(4,4) bond lengths are 3.12 Å. All Nd(1)-Ni(5) bond lengths are 3.30 Å. In the sixth Nd site, Nd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(2); three equivalent Ni(3); six Ni(4,4); and six equivalent Ni(5) atoms. All Nd(1)-Ni(2) bond lengths are 2.91 Å. All Nd(1)-Ni(3) bond lengths are 2.91 Å. All Nd(1)-Ni(4,4) bond lengths are 3.12 Å. All Nd(1)-Ni(5) bond lengths are 3.30 Å. There are eight inequivalent Ni sites. In the first Ni site, Ni(4) is bonded to four Nd(1,1); two equivalent Ni(2); two equivalent Ni(3); and four equivalent Ni(4) atoms to form NiNd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Nd4Ni8 cuboctahedra, corners with twelve equivalent Ni(5)Nd5Ni7 cuboctahedra, edges with two equivalent Ni(4)Nd4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Nd5Ni7 cuboctahedra, faces with two equivalent Ni(5)Nd5Ni7 cuboctahedra, and faces with eight equivalent Ni(4)Nd4Ni8 cuboctahedra. Both Ni(4)-Ni(2) bond lengths are 2.48 Å. Both Ni(4)-Ni(3) bond lengths are 2.47 Å. All Ni(4)-Ni(4) bond lengths are 2.52 Å. In the second Ni site, Ni(1) is bonded to six equivalent Nd(2) and six equivalent Ni(5) atoms to form NiNd6Ni6 cuboctahedra that share corners with twelve equivalent Ni(5)Nd5Ni7 cuboctahedra, edges with six equivalent Ni(1)Nd6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(5)Nd5Ni7 cuboctahedra. All Ni(1)-Ni(5) bond lengths are 2.58 Å. In the third Ni site, Ni(2) is bonded in a 9-coordinate geometry to three equivalent Nd(1); three Ni(4,4); and three equivalent Ni(5) atoms. All Ni(2)-Ni(4,4) bond lengths are 2.48 Å. All Ni(2)-Ni(5) bond lengths are 2.44 Å. In the fourth Ni site, Ni(4) is bonded to four Nd(1,1); two equivalent Ni(2); two equivalent Ni(3); and four Ni(4,4) atoms to form NiNd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Nd4Ni8 cuboctahedra; corners with twelve equivalent Ni(5)Nd5Ni7 cuboctahedra; edges with two equivalent Ni(4)Nd4Ni8 cuboctahedra; edges with eight equivalent Ni(5)Nd5Ni7 cuboctahedra; faces with two equivalent Ni(5)Nd5Ni7 cuboctahedra; and faces with eight Ni(4,4)Nd4Ni8 cuboctahedra. Both Ni(4)-Nd(1) bond lengths are 3.12 Å. Both Ni(4)-Ni(2) bond lengths are 2.48 Å. Both Ni(4)-Ni(3) bond lengths are 2.47 Å. All Ni(4)-Ni(4,4) bond lengths are 2.52 Å. In the fifth Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Nd(1); three Ni(4,4); and three equivalent Ni(5) atoms. The Ni(3)-Ni(4) bond length is 2.47 Å. All Ni(3)-Ni(5) bond lengths are 2.45 Å. In the sixth Ni site, Ni(4) is bonded to four Nd(1,1); two equivalent Ni(2); two equivalent Ni(3); and four equivalent Ni(4) atoms to form NiNd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Nd4Ni8 cuboctahedra, corners with twelve equivalent Ni(5)Nd5Ni7 cuboctahedra, edges with two equivalent Ni(4)Nd4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Nd5Ni7 cuboctahedra, faces with two equivalent Ni(5)Nd5Ni7 cuboctahedra, and faces with eight equivalent Ni(4)Nd4Ni8 cuboctahedra. Both Ni(4)-Ni(3) bond lengths are 2.47 Å. All Ni(4)-Ni(4) bond lengths are 2.52 Å. In the seventh Ni site, Ni(4) is bonded to four Nd(1,1); two equivalent Ni(2); two equivalent Ni(3); and four Ni(4,4) atoms to form NiNd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Nd4Ni8 cuboctahedra; corners with twelve equivalent Ni(5)Nd5Ni7 cuboctahedra; edges with two equivalent Ni(4)Nd4Ni8 cuboctahedra; edges with eight equivalent Ni(5)Nd5Ni7 cuboctahedra; faces with two equivalent Ni(5)Nd5Ni7 cuboctahedra; and faces with eight Ni(4,4)Nd4Ni8 cuboctahedra. Both Ni(4)-Ni(4) bond lengths are 2.52 Å. In the eighth Ni site, Ni(5) is bonded to two equivalent Nd(1), three equivalent Nd(2), one Ni(1), one Ni(2), one Ni(3), and four equivalent Ni(5) atoms to form distorted NiNd5Ni7 cuboctahedra that share corners with two equivalent Ni(1)Nd6Ni6 cuboctahedra; corners with six Ni(4,4)Nd4Ni8 cuboctahedra; corners with nine equivalent Ni(5)Nd5Ni7 cuboctahedra; edges with four Ni(4,4)Nd4Ni8 cuboctahedra; edges with four equivalent Ni(5)Nd5Ni7 cuboctahedra;  a faceface with one Ni(4)Nd4Ni8 cuboctahedra; faces with three equivalent Ni(1)Nd6Ni6 cuboctahedra; and faces with ten equivalent Ni(5)Nd5Ni7 cuboctahedra. All Ni(5)-Ni(5) bond lengths are 2.52 Å.