DOE OSTI2020
Ho5Bi3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are four inequivalent Ho sites. In the first Ho site, Ho is bonded to five Bi atoms to form distorted HoBi5 trigonal bipyramids that share corners with six equivalent HoBi6 octahedra, corners with four equivalent HoBi5 square pyramids, edges with two equivalent HoBi6 octahedra, an edgeedge with one HoBi5 square pyramid, edges with two equivalent HoBi5 trigonal bipyramids, and a faceface with one HoBi5 square pyramid. The corner-sharing octahedra tilt angles range from 31–40°. There are a spread of Ho–Bi bond distances ranging from 3.13–3.37 Å. In the second Ho site, Ho is bonded in a 5-coordinate geometry to five Bi atoms. There are a spread of Ho–Bi bond distances ranging from 3.10–3.50 Å. In the third Ho site, Ho is bonded to five Bi atoms to form distorted HoBi5 square pyramids that share corners with five equivalent HoBi6 octahedra, corners with four equivalent HoBi5 trigonal bipyramids, an edgeedge with one HoBi6 octahedra, edges with two equivalent HoBi5 square pyramids, an edgeedge with one HoBi5 trigonal bipyramid, a faceface with one HoBi6 octahedra, and a faceface with one HoBi5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 36–46°. There are a spread of Ho–Bi bond distances ranging from 3.17–3.25 Å. In the fourth Ho site, Ho is bonded to six Bi atoms to form distorted HoBi6 octahedra that share corners with five equivalent HoBi5 square pyramids, corners with six equivalent HoBi5 trigonal bipyramids, an edgeedge with one HoBi5 square pyramid, edges with two equivalent HoBi5 trigonal bipyramids, faces with two equivalent HoBi6 octahedra, and a faceface with one HoBi5 square pyramid. There are a spread of Ho–Bi bond distances ranging from 3.12–3.43 Å. There are two inequivalent Bi sites. In the first Bi site, Bi is bonded in a 8-coordinate geometry to eight Ho atoms. In the second Bi site, Bi is bonded in a 9-coordinate geometry to nine Ho atoms.