Ho3As is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to four equivalent Ho(1), four equivalent Ho(2), and four equivalent As(1) atoms to form distorted HoHo8As4 cuboctahedra that share corners with twelve equivalent Ho(1)Ho8As4 cuboctahedra, edges with eight equivalent Ho(1)Ho8As4 cuboctahedra, edges with eight equivalent As(1)Ho12 cuboctahedra, faces with four equivalent As(1)Ho12 cuboctahedra, and faces with ten equivalent Ho(1)Ho8As4 cuboctahedra. In the second Ho site, Ho(2) is bonded in a square co-planar geometry to eight equivalent Ho(1) and four equivalent As(1) atoms. As(1) is bonded to four equivalent Ho(2) and eight equivalent Ho(1) atoms to form AsHo12 cuboctahedra that share corners with four equivalent As(1)Ho12 cuboctahedra, edges with eight equivalent As(1)Ho12 cuboctahedra, edges with sixteen equivalent Ho(1)Ho8As4 cuboctahedra, faces with four equivalent As(1)Ho12 cuboctahedra, and faces with eight equivalent Ho(1)Ho8As4 cuboctahedra.
Ho3As is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to four equivalent Ho(1), four equivalent Ho(2), and four equivalent As(1) atoms to form distorted HoHo8As4 cuboctahedra that share corners with twelve equivalent Ho(1)Ho8As4 cuboctahedra, edges with eight equivalent Ho(1)Ho8As4 cuboctahedra, edges with eight equivalent As(1)Ho12 cuboctahedra, faces with four equivalent As(1)Ho12 cuboctahedra, and faces with ten equivalent Ho(1)Ho8As4 cuboctahedra. All Ho(1)-Ho(1) bond lengths are 3.16 Å. All Ho(1)-Ho(2) bond lengths are 3.41 Å. All Ho(1)-As(1) bond lengths are 3.41 Å. In the second Ho site, Ho(2) is bonded in a square co-planar geometry to eight equivalent Ho(1) and four equivalent As(1) atoms. All Ho(2)-As(1) bond lengths are 3.16 Å. As(1) is bonded to four equivalent Ho(2) and eight equivalent Ho(1) atoms to form AsHo12 cuboctahedra that share corners with four equivalent As(1)Ho12 cuboctahedra, edges with eight equivalent As(1)Ho12 cuboctahedra, edges with sixteen equivalent Ho(1)Ho8As4 cuboctahedra, faces with four equivalent As(1)Ho12 cuboctahedra, and faces with eight equivalent Ho(1)Ho8As4 cuboctahedra.