HoPtAs crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to six equivalent Pt(1) and six equivalent As(1) atoms to form a mixture of face and edge-sharing HoAs6Pt6 cuboctahedra. In the second Ho site, Ho(2) is bonded to six equivalent Pt(1) and six equivalent As(1) atoms to form a mixture of distorted face and edge-sharing HoAs6Pt6 cuboctahedra. Pt(1) is bonded in a 9-coordinate geometry to three equivalent Ho(1), three equivalent Ho(2), and three equivalent As(1) atoms. As(1) is bonded in a 9-coordinate geometry to three equivalent Ho(1), three equivalent Ho(2), and three equivalent Pt(1) atoms.
HoPtAs crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to six equivalent Pt(1) and six equivalent As(1) atoms to form a mixture of face and edge-sharing HoAs6Pt6 cuboctahedra. All Ho(1)-Pt(1) bond lengths are 3.21 Å. All Ho(1)-As(1) bond lengths are 3.03 Å. In the second Ho site, Ho(2) is bonded to six equivalent Pt(1) and six equivalent As(1) atoms to form a mixture of distorted face and edge-sharing HoAs6Pt6 cuboctahedra. All Ho(2)-Pt(1) bond lengths are 3.01 Å. All Ho(2)-As(1) bond lengths are 3.19 Å. Pt(1) is bonded in a 9-coordinate geometry to three equivalent Ho(1), three equivalent Ho(2), and three equivalent As(1) atoms. All Pt(1)-As(1) bond lengths are 2.47 Å. As(1) is bonded in a 9-coordinate geometry to three equivalent Ho(1), three equivalent Ho(2), and three equivalent Pt(1) atoms.