Tb5Ni2Bi crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded to four equivalent Ni(1) and two equivalent Bi(1) atoms to form distorted TbNi4Bi2 octahedra that share corners with six equivalent Tb(1)Ni4Bi2 octahedra, corners with sixteen equivalent Tb(2)Ni3Bi2 square pyramids, and faces with eight equivalent Tb(2)Ni3Bi2 square pyramids. The corner-sharing octahedral tilt angles range from 0-50°. In the second Tb site, Tb(2) is bonded to three equivalent Ni(1) and two equivalent Bi(1) atoms to form distorted TbNi3Bi2 square pyramids that share corners with four equivalent Tb(1)Ni4Bi2 octahedra, corners with twelve equivalent Tb(2)Ni3Bi2 square pyramids, edges with seven equivalent Tb(2)Ni3Bi2 square pyramids, faces with two equivalent Tb(1)Ni4Bi2 octahedra, and  a faceface with one Tb(2)Ni3Bi2 square pyramid. The corner-sharing octahedral tilt angles range from 42-61°. Ni(1) is bonded in a 8-coordinate geometry to two equivalent Tb(1) and six equivalent Tb(2) atoms. Bi(1) is bonded in a distorted q6 geometry to two equivalent Tb(1) and eight equivalent Tb(2) atoms.
Tb5Ni2Bi crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded to four equivalent Ni(1) and two equivalent Bi(1) atoms to form distorted TbNi4Bi2 octahedra that share corners with six equivalent Tb(1)Ni4Bi2 octahedra, corners with sixteen equivalent Tb(2)Ni3Bi2 square pyramids, and faces with eight equivalent Tb(2)Ni3Bi2 square pyramids. The corner-sharing octahedral tilt angles range from 0-50°. All Tb(1)-Ni(1) bond lengths are 3.01 Å. Both Tb(1)-Bi(1) bond lengths are 3.41 Å. In the second Tb site, Tb(2) is bonded to three equivalent Ni(1) and two equivalent Bi(1) atoms to form distorted TbNi3Bi2 square pyramids that share corners with four equivalent Tb(1)Ni4Bi2 octahedra, corners with twelve equivalent Tb(2)Ni3Bi2 square pyramids, edges with seven equivalent Tb(2)Ni3Bi2 square pyramids, faces with two equivalent Tb(1)Ni4Bi2 octahedra, and  a faceface with one Tb(2)Ni3Bi2 square pyramid. The corner-sharing octahedral tilt angles range from 42-61°. There are two shorter (2.88 Å) and one longer (2.93 Å) Tb(2)-Ni(1) bond length. Both Tb(2)-Bi(1) bond lengths are 3.32 Å. Ni(1) is bonded in a 8-coordinate geometry to two equivalent Tb(1) and six equivalent Tb(2) atoms. Bi(1) is bonded in a distorted q6 geometry to two equivalent Tb(1) and eight equivalent Tb(2) atoms.