Dy5Bi3 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Dy sites. In the first Dy site, Dy(1) is bonded to one Bi(1) and four equivalent Bi(2) atoms to form distorted DyBi5 trigonal bipyramids that share corners with six equivalent Dy(4)Bi6 octahedra, corners with four equivalent Dy(3)Bi5 square pyramids, edges with two equivalent Dy(4)Bi6 octahedra,  an edgeedge with one Dy(3)Bi5 square pyramid, edges with two equivalent Dy(1)Bi5 trigonal bipyramids, and  a faceface with one Dy(3)Bi5 square pyramid. The corner-sharing octahedral tilt angles range from 31-41°. In the second Dy site, Dy(2) is bonded in a 5-coordinate geometry to two equivalent Bi(1) and three equivalent Bi(2) atoms. In the third Dy site, Dy(3) is bonded to one Bi(1) and four equivalent Bi(2) atoms to form distorted DyBi5 square pyramids that share corners with five equivalent Dy(4)Bi6 octahedra, corners with four equivalent Dy(1)Bi5 trigonal bipyramids,  an edgeedge with one Dy(4)Bi6 octahedra, edges with two equivalent Dy(3)Bi5 square pyramids,  an edgeedge with one Dy(1)Bi5 trigonal bipyramid,  a faceface with one Dy(4)Bi6 octahedra, and  a faceface with one Dy(1)Bi5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 37-46°. In the fourth Dy site, Dy(4) is bonded to two equivalent Bi(1) and four equivalent Bi(2) atoms to form distorted DyBi6 octahedra that share corners with five equivalent Dy(3)Bi5 square pyramids, corners with six equivalent Dy(1)Bi5 trigonal bipyramids,  an edgeedge with one Dy(3)Bi5 square pyramid, edges with two equivalent Dy(1)Bi5 trigonal bipyramids, faces with two equivalent Dy(4)Bi6 octahedra, and  a faceface with one Dy(3)Bi5 square pyramid. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 8-coordinate geometry to one Dy(1), one Dy(3), two equivalent Dy(4), and four equivalent Dy(2) atoms. In the second Bi site, Bi(2) is bonded in a 9-coordinate geometry to two equivalent Dy(1), two equivalent Dy(3), two equivalent Dy(4), and three equivalent Dy(2) atoms.
Dy5Bi3 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Dy sites. In the first Dy site, Dy(1) is bonded to one Bi(1) and four equivalent Bi(2) atoms to form distorted DyBi5 trigonal bipyramids that share corners with six equivalent Dy(4)Bi6 octahedra, corners with four equivalent Dy(3)Bi5 square pyramids, edges with two equivalent Dy(4)Bi6 octahedra,  an edgeedge with one Dy(3)Bi5 square pyramid, edges with two equivalent Dy(1)Bi5 trigonal bipyramids, and  a faceface with one Dy(3)Bi5 square pyramid. The corner-sharing octahedral tilt angles range from 31-41°. The Dy(1)-Bi(1) bond length is 3.12 Å. There are two shorter (3.20 Å) and two longer (3.36 Å) Dy(1)-Bi(2) bond lengths. In the second Dy site, Dy(2) is bonded in a 5-coordinate geometry to two equivalent Bi(1) and three equivalent Bi(2) atoms. There is one shorter (3.09 Å) and one longer (3.18 Å) Dy(2)-Bi(1) bond length. There are a spread of Dy(2)-Bi(2) bond distances ranging from 3.41-3.49 Å. In the third Dy site, Dy(3) is bonded to one Bi(1) and four equivalent Bi(2) atoms to form distorted DyBi5 square pyramids that share corners with five equivalent Dy(4)Bi6 octahedra, corners with four equivalent Dy(1)Bi5 trigonal bipyramids,  an edgeedge with one Dy(4)Bi6 octahedra, edges with two equivalent Dy(3)Bi5 square pyramids,  an edgeedge with one Dy(1)Bi5 trigonal bipyramid,  a faceface with one Dy(4)Bi6 octahedra, and  a faceface with one Dy(1)Bi5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 37-46°. The Dy(3)-Bi(1) bond length is 3.18 Å. There are two shorter (3.19 Å) and two longer (3.24 Å) Dy(3)-Bi(2) bond lengths. In the fourth Dy site, Dy(4) is bonded to two equivalent Bi(1) and four equivalent Bi(2) atoms to form distorted DyBi6 octahedra that share corners with five equivalent Dy(3)Bi5 square pyramids, corners with six equivalent Dy(1)Bi5 trigonal bipyramids,  an edgeedge with one Dy(3)Bi5 square pyramid, edges with two equivalent Dy(1)Bi5 trigonal bipyramids, faces with two equivalent Dy(4)Bi6 octahedra, and  a faceface with one Dy(3)Bi5 square pyramid. There is one shorter (3.12 Å) and one longer (3.42 Å) Dy(4)-Bi(1) bond length. There are two shorter (3.20 Å) and two longer (3.43 Å) Dy(4)-Bi(2) bond lengths. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 8-coordinate geometry to one Dy(1), one Dy(3), two equivalent Dy(4), and four equivalent Dy(2) atoms. In the second Bi site, Bi(2) is bonded in a 9-coordinate geometry to two equivalent Dy(1), two equivalent Dy(3), two equivalent Dy(4), and three equivalent Dy(2) atoms.