Tm5Ni2Bi crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to four equivalent Ni(1) and two equivalent Bi(1) atoms to form distorted TmNi4Bi2 octahedra that share corners with six equivalent Tm(1)Ni4Bi2 octahedra, corners with sixteen equivalent Tm(2)Ni3Bi2 square pyramids, and faces with eight equivalent Tm(2)Ni3Bi2 square pyramids. The corner-sharing octahedral tilt angles range from 0-50°. In the second Tm site, Tm(2) is bonded to three equivalent Ni(1) and two equivalent Bi(1) atoms to form distorted TmNi3Bi2 square pyramids that share corners with four equivalent Tm(1)Ni4Bi2 octahedra, corners with twelve equivalent Tm(2)Ni3Bi2 square pyramids, edges with seven equivalent Tm(2)Ni3Bi2 square pyramids, faces with two equivalent Tm(1)Ni4Bi2 octahedra, and  a faceface with one Tm(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 Tm(1) and six equivalent Tm(2) atoms. Bi(1) is bonded in a distorted q6 geometry to two equivalent Tm(1) and eight equivalent Tm(2) atoms.
Tm5Ni2Bi crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to four equivalent Ni(1) and two equivalent Bi(1) atoms to form distorted TmNi4Bi2 octahedra that share corners with six equivalent Tm(1)Ni4Bi2 octahedra, corners with sixteen equivalent Tm(2)Ni3Bi2 square pyramids, and faces with eight equivalent Tm(2)Ni3Bi2 square pyramids. The corner-sharing octahedral tilt angles range from 0-50°. All Tm(1)-Ni(1) bond lengths are 2.93 Å. Both Tm(1)-Bi(1) bond lengths are 3.35 Å. In the second Tm site, Tm(2) is bonded to three equivalent Ni(1) and two equivalent Bi(1) atoms to form distorted TmNi3Bi2 square pyramids that share corners with four equivalent Tm(1)Ni4Bi2 octahedra, corners with twelve equivalent Tm(2)Ni3Bi2 square pyramids, edges with seven equivalent Tm(2)Ni3Bi2 square pyramids, faces with two equivalent Tm(1)Ni4Bi2 octahedra, and  a faceface with one Tm(2)Ni3Bi2 square pyramid. The corner-sharing octahedral tilt angles range from 42-61°. There are two shorter (2.81 Å) and one longer (2.86 Å) Tm(2)-Ni(1) bond length. Both Tm(2)-Bi(1) bond lengths are 3.25 Å. Ni(1) is bonded in a 8-coordinate geometry to two equivalent Tm(1) and six equivalent Tm(2) atoms. Bi(1) is bonded in a distorted q6 geometry to two equivalent Tm(1) and eight equivalent Tm(2) atoms.