Ce21Fe8C12Bi7 crystallizes in the cubic Fm-3m space group. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a distorted L-shaped geometry to two equivalent C(1), one Bi(2), and two equivalent Bi(1) atoms. In the second Ce site, Ce(2) is bonded in a 6-coordinate geometry to three equivalent C(1) and three equivalent Bi(1) atoms. In the third Ce site, Ce(3) is bonded in an octahedral geometry to six equivalent Bi(1) atoms. Fe(1) is bonded in a trigonal planar geometry to three equivalent C(1) atoms. C(1) is bonded to two equivalent Ce(1), two equivalent Ce(2), and two equivalent Fe(1) atoms to form distorted CCe4Fe2 octahedra that share corners with two equivalent Bi(2)Ce12 cuboctahedra and edges with five equivalent C(1)Ce4Fe2 octahedra. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 9-coordinate geometry to one Ce(3), four equivalent Ce(1), and four equivalent Ce(2) atoms. In the second Bi site, Bi(2) is bonded to twelve equivalent Ce(1) atoms to form BiCe12 cuboctahedra that share corners with twenty-four equivalent C(1)Ce4Fe2 octahedra. The corner-sharing octahedral tilt angles are 43°.
Ce21Fe8C12Bi7 crystallizes in the cubic Fm-3m space group. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a distorted L-shaped geometry to two equivalent C(1), one Bi(2), and two equivalent Bi(1) atoms. Both Ce(1)-C(1) bond lengths are 2.46 Å. The Ce(1)-Bi(2) bond length is 3.91 Å. Both Ce(1)-Bi(1) bond lengths are 3.38 Å. In the second Ce site, Ce(2) is bonded in a 6-coordinate geometry to three equivalent C(1) and three equivalent Bi(1) atoms. All Ce(2)-C(1) bond lengths are 2.60 Å. All Ce(2)-Bi(1) bond lengths are 3.35 Å. In the third Ce site, Ce(3) is bonded in an octahedral geometry to six equivalent Bi(1) atoms. All Ce(3)-Bi(1) bond lengths are 3.35 Å. Fe(1) is bonded in a trigonal planar geometry to three equivalent C(1) atoms. All Fe(1)-C(1) bond lengths are 1.93 Å. C(1) is bonded to two equivalent Ce(1), two equivalent Ce(2), and two equivalent Fe(1) atoms to form distorted CCe4Fe2 octahedra that share corners with two equivalent Bi(2)Ce12 cuboctahedra and edges with five equivalent C(1)Ce4Fe2 octahedra. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 9-coordinate geometry to one Ce(3), four equivalent Ce(1), and four equivalent Ce(2) atoms. In the second Bi site, Bi(2) is bonded to twelve equivalent Ce(1) atoms to form BiCe12 cuboctahedra that share corners with twenty-four equivalent C(1)Ce4Fe2 octahedra. The corner-sharing octahedral tilt angles are 43°.