Materials Data on Sm3AlNi8 by Materials Project

Sm3Ni8Al crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Sm sites. In the first Sm site, Sm is bonded in a 12-coordinate geometry to twelve Ni atoms. There are a spread of Sm–Ni bond distances ranging from 2.92–3.12 Å. In the second Sm site, Sm is bonded in a 6-coordinate geometry to fifteen Ni and three equivalent Al atoms. There are three shorter (2.96 Å) and twelve longer (3.24 Å) Sm–Ni bond lengths. All Sm–Al bond lengths are 2.96 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded to five Sm, six Ni, and one Al atom to form distorted NiSm5AlNi6 cuboctahedra that share corners with two equivalent AlSm3Ni9 cuboctahedra, corners with nineteen NiSm5AlNi6 cuboctahedra, edges with eight equivalent NiSm5AlNi6 cuboctahedra, faces with three equivalent AlSm3Ni9 cuboctahedra, and faces with seventeen NiSm5AlNi6 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.47–2.57 Å. The Ni–Al bond length is 2.48 Å. In the second Ni site, Ni is bonded to three equivalent Sm, six equivalent Ni, and three equivalent Al atoms to form NiSm3Al3Ni6 cuboctahedra that share corners with three equivalent AlSm3Ni9 cuboctahedra, corners with twelve equivalent NiSm5AlNi6 cuboctahedra, edges with six equivalent NiSm3Al3Ni6 cuboctahedra, faces with three equivalent AlSm3Ni9 cuboctahedra, and faces with twenty NiSm5AlNi6 cuboctahedra. All Ni–Al bond lengths are 2.96 Å. In the third Ni site, Ni is bonded to six equivalent Sm and six equivalent Ni atoms to form NiSm6Ni6 cuboctahedra that share corners with six equivalent AlSm3Ni9 cuboctahedra, corners with twelve equivalent NiSm5AlNi6 cuboctahedra, edges with six equivalent NiSm6Ni6 cuboctahedra, and faces with twenty NiSm5AlNi6 cuboctahedra. Al is bonded to three equivalent Sm and nine Ni atoms to form distorted AlSm3Ni9 cuboctahedra that share corners with twenty-one NiSm5AlNi6 cuboctahedra, edges with six equivalent AlSm3Ni9 cuboctahedra, and faces with twenty-one NiSm5AlNi6 cuboctahedra.