Ce2Ni7 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 12-coordinate geometry to three equivalent Ni(1) and nine equivalent Ni(5) atoms. In the second Ce site, Ce(2) is bonded in a 6-coordinate geometry to three equivalent Ni(2), three equivalent Ni(3), six equivalent Ni(4), and six equivalent Ni(5) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to six equivalent Ce(1) and six equivalent Ni(5) atoms to form NiCe6Ni6 cuboctahedra that share corners with twelve equivalent Ni(5)Ce5Ni7 cuboctahedra, edges with six equivalent Ni(1)Ce6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(5)Ce5Ni7 cuboctahedra. In the second Ni site, Ni(2) is bonded in a 12-coordinate geometry to three equivalent Ce(2), three equivalent Ni(3), three equivalent Ni(4), and three equivalent Ni(5) atoms. In the third Ni site, Ni(3) is bonded in a 12-coordinate geometry to three equivalent Ce(2), three equivalent Ni(2), three equivalent Ni(4), and three equivalent Ni(5) atoms. In the fourth Ni site, Ni(4) is bonded to four equivalent Ce(2), two equivalent Ni(2), two equivalent Ni(3), and four equivalent Ni(4) atoms to form NiCe4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Ce4Ni8 cuboctahedra, corners with twelve equivalent Ni(5)Ce5Ni7 cuboctahedra, edges with two equivalent Ni(4)Ce4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Ce5Ni7 cuboctahedra, faces with two equivalent Ni(5)Ce5Ni7 cuboctahedra, and faces with eight equivalent Ni(4)Ce4Ni8 cuboctahedra. In the fifth Ni site, Ni(5) is bonded to two equivalent Ce(2), three equivalent Ce(1), one Ni(1), one Ni(2), one Ni(3), and four equivalent Ni(5) atoms to form distorted NiCe5Ni7 cuboctahedra that share corners with two equivalent Ni(1)Ce6Ni6 cuboctahedra, corners with six equivalent Ni(4)Ce4Ni8 cuboctahedra, corners with nine equivalent Ni(5)Ce5Ni7 cuboctahedra, edges with four equivalent Ni(4)Ce4Ni8 cuboctahedra, edges with four equivalent Ni(5)Ce5Ni7 cuboctahedra,  a faceface with one Ni(4)Ce4Ni8 cuboctahedra, faces with three equivalent Ni(1)Ce6Ni6 cuboctahedra, and faces with ten equivalent Ni(5)Ce5Ni7 cuboctahedra.
Ce2Ni7 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 12-coordinate geometry to three equivalent Ni(1) and nine equivalent Ni(5) atoms. All Ce(1)-Ni(1) bond lengths are 2.93 Å. There are six shorter (2.79 Å) and three longer (3.17 Å) Ce(1)-Ni(5) bond lengths. In the second Ce site, Ce(2) is bonded in a 6-coordinate geometry to three equivalent Ni(2), three equivalent Ni(3), six equivalent Ni(4), and six equivalent Ni(5) atoms. All Ce(2)-Ni(2) bond lengths are 2.84 Å. All Ce(2)-Ni(3) bond lengths are 2.84 Å. All Ce(2)-Ni(4) bond lengths are 3.07 Å. All Ce(2)-Ni(5) bond lengths are 3.29 Å. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to six equivalent Ce(1) and six equivalent Ni(5) atoms to form NiCe6Ni6 cuboctahedra that share corners with twelve equivalent Ni(5)Ce5Ni7 cuboctahedra, edges with six equivalent Ni(1)Ce6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(5)Ce5Ni7 cuboctahedra. All Ni(1)-Ni(5) bond lengths are 2.52 Å. In the second Ni site, Ni(2) is bonded in a 12-coordinate geometry to three equivalent Ce(2), three equivalent Ni(3), three equivalent Ni(4), and three equivalent Ni(5) atoms. All Ni(2)-Ni(3) bond lengths are 2.83 Å. All Ni(2)-Ni(4) bond lengths are 2.46 Å. All Ni(2)-Ni(5) bond lengths are 2.47 Å. In the third Ni site, Ni(3) is bonded in a 12-coordinate geometry to three equivalent Ce(2), three equivalent Ni(2), three equivalent Ni(4), and three equivalent Ni(5) atoms. All Ni(3)-Ni(4) bond lengths are 2.47 Å. All Ni(3)-Ni(5) bond lengths are 2.46 Å. In the fourth Ni site, Ni(4) is bonded to four equivalent Ce(2), two equivalent Ni(2), two equivalent Ni(3), and four equivalent Ni(4) atoms to form NiCe4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Ce4Ni8 cuboctahedra, corners with twelve equivalent Ni(5)Ce5Ni7 cuboctahedra, edges with two equivalent Ni(4)Ce4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Ce5Ni7 cuboctahedra, faces with two equivalent Ni(5)Ce5Ni7 cuboctahedra, and faces with eight equivalent Ni(4)Ce4Ni8 cuboctahedra. There are two shorter (2.45 Å) and two longer (2.46 Å) Ni(4)-Ni(4) bond lengths. In the fifth Ni site, Ni(5) is bonded to two equivalent Ce(2), three equivalent Ce(1), one Ni(1), one Ni(2), one Ni(3), and four equivalent Ni(5) atoms to form distorted NiCe5Ni7 cuboctahedra that share corners with two equivalent Ni(1)Ce6Ni6 cuboctahedra, corners with six equivalent Ni(4)Ce4Ni8 cuboctahedra, corners with nine equivalent Ni(5)Ce5Ni7 cuboctahedra, edges with four equivalent Ni(4)Ce4Ni8 cuboctahedra, edges with four equivalent Ni(5)Ce5Ni7 cuboctahedra,  a faceface with one Ni(4)Ce4Ni8 cuboctahedra, faces with three equivalent Ni(1)Ce6Ni6 cuboctahedra, and faces with ten equivalent Ni(5)Ce5Ni7 cuboctahedra. There are two shorter (2.45 Å) and two longer (2.46 Å) Ni(5)-Ni(5) bond lengths.