DOE OSTI2020
HoGa3 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Ho sites. In the first Ho site, Ho is bonded to twelve Ga atoms to form HoGa12 cuboctahedra that share corners with six equivalent GaHo4Ga8 cuboctahedra, corners with nine HoGa12 cuboctahedra, edges with twelve equivalent GaHo4Ga8 cuboctahedra, faces with seven HoGa12 cuboctahedra, and faces with nine equivalent GaHo4Ga8 cuboctahedra. There are a spread of Ho–Ga bond distances ranging from 3.01–3.05 Å. In the second Ho site, Ho is bonded to twelve Ga atoms to form HoGa12 cuboctahedra that share corners with twelve HoGa12 cuboctahedra, edges with fifteen GaHo4Ga8 cuboctahedra, faces with six HoGa12 cuboctahedra, and faces with six GaHo4Ga8 cuboctahedra. There are a spread of Ho–Ga bond distances ranging from 2.96–3.05 Å. In the third Ho site, Ho is bonded to twelve Ga atoms to form HoGa12 cuboctahedra that share corners with six equivalent HoGa12 cuboctahedra, corners with twelve equivalent GaHo4Ga8 cuboctahedra, edges with six equivalent GaHo4Ga8 cuboctahedra, faces with six equivalent GaHo4Ga8 cuboctahedra, and faces with eight HoGa12 cuboctahedra. There are six shorter (3.04 Å) and six longer (3.06 Å) Ho–Ga bond lengths. There are three inequivalent Ga sites. In the first Ga site, Ga is bonded in a 10-coordinate geometry to four Ho and six Ga atoms. There are a spread of Ga–Ga bond distances ranging from 2.70–2.94 Å. In the second Ga site, Ga is bonded to four Ho and eight Ga atoms to form distorted GaHo4Ga8 cuboctahedra that share corners with two equivalent HoGa12 cuboctahedra, corners with ten GaHo4Ga8 cuboctahedra, edges with seven HoGa12 cuboctahedra, edges with eight equivalent GaHo4Ga8 cuboctahedra, faces with four HoGa12 cuboctahedra, and faces with ten GaHo4Ga8 cuboctahedra. There are a spread of Ga–Ga bond distances ranging from 2.92–3.06 Å. In the third Ga site, Ga is bonded to four Ho and eight Ga atoms to form distorted GaHo4Ga8 cuboctahedra that share corners with four equivalent HoGa12 cuboctahedra, corners with fourteen GaHo4Ga8 cuboctahedra, edges with four equivalent GaHo4Ga8 cuboctahedra, edges with six HoGa12 cuboctahedra, faces with four HoGa12 cuboctahedra, and faces with six GaHo4Ga8 cuboctahedra. All Ga–Ga bond lengths are 3.04 Å.