DOE OSTI2020
ThNi3Al2 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. Th is bonded in a distorted hexagonal planar geometry to ten Ni and eight equivalent Al atoms. There are a spread of Th–Ni bond distances ranging from 2.85–3.32 Å. All Th–Al bond lengths are 3.26 Å. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded to four equivalent Th, four equivalent Ni, and four equivalent Al atoms to form distorted NiTh4Al4Ni4 cuboctahedra that share corners with eight equivalent NiTh4Al4Ni4 cuboctahedra, corners with eight equivalent AlTh4Ni6 cuboctahedra, edges with two equivalent NiTh4Al4Ni4 cuboctahedra, edges with twelve equivalent AlTh4Ni6 cuboctahedra, faces with two equivalent NiTh4Al4Ni4 cuboctahedra, and faces with four equivalent AlTh4Ni6 cuboctahedra. All Ni–Ni bond lengths are 2.54 Å. All Ni–Al bond lengths are 2.52 Å. In the second Ni site, Ni is bonded in a 12-coordinate geometry to three equivalent Th, two equivalent Ni, and four equivalent Al atoms. All Ni–Al bond lengths are 2.53 Å. Al is bonded to four equivalent Th and six Ni atoms to form distorted AlTh4Ni6 cuboctahedra that share corners with four equivalent NiTh4Al4Ni4 cuboctahedra, corners with ten equivalent AlTh4Ni6 cuboctahedra, edges with six equivalent NiTh4Al4Ni4 cuboctahedra, edges with six equivalent AlTh4Ni6 cuboctahedra, faces with two equivalent NiTh4Al4Ni4 cuboctahedra, and faces with six equivalent AlTh4Ni6 cuboctahedra.