Ho5Bi3 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to one Bi(1) and four equivalent Bi(2) atoms to form distorted HoBi5 trigonal bipyramids that share corners with six equivalent Ho(4)Bi6 octahedra, corners with four equivalent Ho(3)Bi5 square pyramids, edges with two equivalent Ho(4)Bi6 octahedra,  an edgeedge with one Ho(3)Bi5 square pyramid, edges with two equivalent Ho(1)Bi5 trigonal bipyramids, and  a faceface with one Ho(3)Bi5 square pyramid. The corner-sharing octahedral tilt angles range from 31-40°. In the second Ho site, Ho(2) is bonded in a 5-coordinate geometry to two equivalent Bi(1) and three equivalent Bi(2) atoms. In the third Ho site, Ho(3) is bonded to one Bi(1) and four equivalent Bi(2) atoms to form distorted HoBi5 square pyramids that share corners with five equivalent Ho(4)Bi6 octahedra, corners with four equivalent Ho(1)Bi5 trigonal bipyramids,  an edgeedge with one Ho(4)Bi6 octahedra, edges with two equivalent Ho(3)Bi5 square pyramids,  an edgeedge with one Ho(1)Bi5 trigonal bipyramid,  a faceface with one Ho(4)Bi6 octahedra, and  a faceface with one Ho(1)Bi5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 36-46°. In the fourth Ho site, Ho(4) is bonded to two equivalent Bi(1) and four equivalent Bi(2) atoms to form distorted HoBi6 octahedra that share corners with five equivalent Ho(3)Bi5 square pyramids, corners with six equivalent Ho(1)Bi5 trigonal bipyramids,  an edgeedge with one Ho(3)Bi5 square pyramid, edges with two equivalent Ho(1)Bi5 trigonal bipyramids, faces with two equivalent Ho(4)Bi6 octahedra, and  a faceface with one Ho(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 Ho(1), one Ho(3), two equivalent Ho(4), and four equivalent Ho(2) atoms. In the second Bi site, Bi(2) is bonded in a 9-coordinate geometry to two equivalent Ho(1), two equivalent Ho(3), two equivalent Ho(4), and three equivalent Ho(2) atoms.
Ho5Bi3 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to one Bi(1) and four equivalent Bi(2) atoms to form distorted HoBi5 trigonal bipyramids that share corners with six equivalent Ho(4)Bi6 octahedra, corners with four equivalent Ho(3)Bi5 square pyramids, edges with two equivalent Ho(4)Bi6 octahedra,  an edgeedge with one Ho(3)Bi5 square pyramid, edges with two equivalent Ho(1)Bi5 trigonal bipyramids, and  a faceface with one Ho(3)Bi5 square pyramid. The corner-sharing octahedral tilt angles range from 31-40°. The Ho(1)-Bi(1) bond length is 3.11 Å. There are two shorter (3.18 Å) and two longer (3.35 Å) Ho(1)-Bi(2) bond lengths. In the second Ho site, Ho(2) is bonded in a 5-coordinate geometry to two equivalent Bi(1) and three equivalent Bi(2) atoms. There is one shorter (3.08 Å) and one longer (3.17 Å) Ho(2)-Bi(1) bond length. There are a spread of Ho(2)-Bi(2) bond distances ranging from 3.40-3.48 Å. In the third Ho site, Ho(3) is bonded to one Bi(1) and four equivalent Bi(2) atoms to form distorted HoBi5 square pyramids that share corners with five equivalent Ho(4)Bi6 octahedra, corners with four equivalent Ho(1)Bi5 trigonal bipyramids,  an edgeedge with one Ho(4)Bi6 octahedra, edges with two equivalent Ho(3)Bi5 square pyramids,  an edgeedge with one Ho(1)Bi5 trigonal bipyramid,  a faceface with one Ho(4)Bi6 octahedra, and  a faceface with one Ho(1)Bi5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 36-46°. The Ho(3)-Bi(1) bond length is 3.16 Å. There are two shorter (3.17 Å) and two longer (3.23 Å) Ho(3)-Bi(2) bond lengths. In the fourth Ho site, Ho(4) is bonded to two equivalent Bi(1) and four equivalent Bi(2) atoms to form distorted HoBi6 octahedra that share corners with five equivalent Ho(3)Bi5 square pyramids, corners with six equivalent Ho(1)Bi5 trigonal bipyramids,  an edgeedge with one Ho(3)Bi5 square pyramid, edges with two equivalent Ho(1)Bi5 trigonal bipyramids, faces with two equivalent Ho(4)Bi6 octahedra, and  a faceface with one Ho(3)Bi5 square pyramid. There is one shorter (3.10 Å) and one longer (3.40 Å) Ho(4)-Bi(1) bond length. There are two shorter (3.19 Å) and two longer (3.41 Å) Ho(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 Ho(1), one Ho(3), two equivalent Ho(4), and four equivalent Ho(2) atoms. In the second Bi site, Bi(2) is bonded in a 9-coordinate geometry to two equivalent Ho(1), two equivalent Ho(3), two equivalent Ho(4), and three equivalent Ho(2) atoms.