Dy5Co2Bi crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded to four equivalent Co(1) and two equivalent Bi(1) atoms to form distorted DyCo4Bi2 octahedra that share corners with six equivalent Dy(1)Co4Bi2 octahedra, corners with sixteen equivalent Dy(2)Co3Bi2 square pyramids, and faces with eight equivalent Dy(2)Co3Bi2 square pyramids. The corner-sharing octahedral tilt angles range from 0-49°. In the second Dy site, Dy(2) is bonded to three equivalent Co(1) and two equivalent Bi(1) atoms to form distorted DyCo3Bi2 square pyramids that share corners with four equivalent Dy(1)Co4Bi2 octahedra, corners with twelve equivalent Dy(2)Co3Bi2 square pyramids, edges with seven equivalent Dy(2)Co3Bi2 square pyramids, faces with two equivalent Dy(1)Co4Bi2 octahedra, and  a faceface with one Dy(2)Co3Bi2 square pyramid. The corner-sharing octahedral tilt angles range from 40-60°. Co(1) is bonded in a 8-coordinate geometry to two equivalent Dy(1) and six equivalent Dy(2) atoms. Bi(1) is bonded in a distorted q6 geometry to two equivalent Dy(1) and eight equivalent Dy(2) atoms.
Dy5Co2Bi crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded to four equivalent Co(1) and two equivalent Bi(1) atoms to form distorted DyCo4Bi2 octahedra that share corners with six equivalent Dy(1)Co4Bi2 octahedra, corners with sixteen equivalent Dy(2)Co3Bi2 square pyramids, and faces with eight equivalent Dy(2)Co3Bi2 square pyramids. The corner-sharing octahedral tilt angles range from 0-49°. All Dy(1)-Co(1) bond lengths are 2.98 Å. Both Dy(1)-Bi(1) bond lengths are 3.36 Å. In the second Dy site, Dy(2) is bonded to three equivalent Co(1) and two equivalent Bi(1) atoms to form distorted DyCo3Bi2 square pyramids that share corners with four equivalent Dy(1)Co4Bi2 octahedra, corners with twelve equivalent Dy(2)Co3Bi2 square pyramids, edges with seven equivalent Dy(2)Co3Bi2 square pyramids, faces with two equivalent Dy(1)Co4Bi2 octahedra, and  a faceface with one Dy(2)Co3Bi2 square pyramid. The corner-sharing octahedral tilt angles range from 40-60°. There is one shorter (2.83 Å) and two longer (2.84 Å) Dy(2)-Co(1) bond lengths. Both Dy(2)-Bi(1) bond lengths are 3.32 Å. Co(1) is bonded in a 8-coordinate geometry to two equivalent Dy(1) and six equivalent Dy(2) atoms. Bi(1) is bonded in a distorted q6 geometry to two equivalent Dy(1) and eight equivalent Dy(2) atoms.