Materials Data on Ho3AlNi8 by Materials Project
Ho3Ni8Al crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded in a 12-coordinate geometry to nine equivalent Ni and three equivalent Al atoms. There are six shorter (2.82 Å) and three longer (3.06 Å) Ho–Ni bond lengths. All Ho–Al bond lengths are 3.00 Å. In the second Ho site, Ho is bonded in a distorted hexagonal planar geometry to eighteen Ni atoms. There are six shorter (2.91 Å) and twelve longer (3.21 Å) Ho–Ni bond lengths. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded to five Ho, six Ni, and one Al atom to form distorted NiHo5AlNi6 cuboctahedra that share corners with two equivalent AlHo6Ni6 cuboctahedra, corners with fifteen equivalent NiHo5AlNi6 cuboctahedra, edges with eight equivalent NiHo5AlNi6 cuboctahedra, faces with three equivalent AlHo6Ni6 cuboctahedra, and faces with eleven equivalent NiHo5AlNi6 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.45–2.56 Å. The Ni–Al bond length is 2.48 Å. In the second Ni site, Ni is bonded in a 12-coordinate geometry to three equivalent Ho and six equivalent Ni atoms. In the third Ni site, Ni is bonded in a 12-coordinate geometry to three equivalent Ho and six equivalent Ni atoms. Al is bonded to six equivalent Ho and six equivalent Ni atoms to form distorted AlHo6Ni6 cuboctahedra that share corners with twelve equivalent NiHo5AlNi6 cuboctahedra, edges with six equivalent AlHo6Ni6 cuboctahedra, and faces with eighteen equivalent NiHo5AlNi6 cuboctahedra.