DOE OSTI2020
Ni41Al5B12 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are nine inequivalent Ni sites. In the first Ni site, Ni is bonded to two equivalent Ni, one Al, and three B atoms to form NiAlNi2B3 tetrahedra that share corners with two equivalent AlNi13 tetrahedra, corners with six NiAlNi2B3 tetrahedra, an edgeedge with one AlNi12 cuboctahedra, an edgeedge with one AlNi7 tetrahedra, edges with three NiAlNi2B3 tetrahedra, and faces with two equivalent NiAlNi4B3 tetrahedra. Both Ni–Ni bond lengths are 2.59 Å. The Ni–Al bond length is 2.40 Å. There are one shorter (2.07 Å) and two longer (2.09 Å) Ni–B bond lengths. In the second Ni site, Ni is bonded to four Ni, one Al, and three B atoms to form NiAlNi4B3 tetrahedra that share corners with two equivalent AlNi7 tetrahedra, corners with five NiAlNi2B3 tetrahedra, edges with two equivalent AlNi12 cuboctahedra, an edgeedge with one AlNi13 tetrahedra, edges with three equivalent NiAlNi4B3 tetrahedra, a faceface with one AlNi13 tetrahedra, and faces with four NiAlNi2B3 tetrahedra. All Ni–Ni bond lengths are 2.60 Å. The Ni–Al bond length is 2.40 Å. There are two shorter (2.08 Å) and one longer (2.09 Å) Ni–B bond lengths. In the third Ni site, Ni is bonded to six equivalent Ni, one Al, and three equivalent B atoms to form NiAlNi6B3 tetrahedra that share corners with three equivalent NiAlNi2B3 tetrahedra, edges with three equivalent AlNi12 cuboctahedra, edges with three equivalent NiAlNi6B3 tetrahedra, edges with three equivalent AlNi13 tetrahedra, a faceface with one AlNi13 tetrahedra, and faces with six equivalent NiAlNi4B3 tetrahedra. All Ni–Ni bond lengths are 2.60 Å. The Ni–Al bond length is 2.39 Å. All Ni–B bond lengths are 2.08 Å. In the fourth Ni site, Ni is bonded to one Al and three equivalent B atoms to form a mixture of edge and corner-sharing NiAlB3 tetrahedra. The Ni–Al bond length is 2.40 Å. All Ni–B bond lengths are 2.08 Å. In the fifth Ni site, Ni is bonded in a 2-coordinate geometry to nine Ni, three Al, and two equivalent B atoms. There are a spread of Ni–Ni bond distances ranging from 2.39–2.51 Å. There are one shorter (2.50 Å) and two longer (2.88 Å) Ni–Al bond lengths. Both Ni–B bond lengths are 2.08 Å. In the sixth Ni site, Ni is bonded in a distorted bent 150 degrees geometry to one Ni and two equivalent B atoms. The Ni–Ni bond length is 2.50 Å. Both Ni–B bond lengths are 2.07 Å. In the seventh Ni site, Ni is bonded in a distorted bent 150 degrees geometry to two Ni and two equivalent B atoms. There are one shorter (2.40 Å) and one longer (2.48 Å) Ni–Ni bond lengths. Both Ni–B bond lengths are 2.07 Å. In the eighth Ni site, Ni is bonded in a 2-coordinate geometry to nine Ni, three Al, and two equivalent B atoms. Both Ni–Ni bond lengths are 2.51 Å. There are one shorter (2.52 Å) and two longer (2.87 Å) Ni–Al bond lengths. Both Ni–B bond lengths are 2.08 Å. In the ninth Ni site, Ni is bonded in a cuboctahedral geometry to twelve Ni atoms. There are three inequivalent Al sites. In the first Al site, Al is bonded to seven Ni atoms to form distorted AlNi7 tetrahedra that share corners with three equivalent AlNi13 tetrahedra, corners with six equivalent NiAlNi4B3 tetrahedra, edges with three equivalent NiAlNi2B3 tetrahedra, and a faceface with one AlNi12 cuboctahedra. In the second Al site, Al is bonded to thirteen Ni atoms to form distorted AlNi13 tetrahedra that share corners with three equivalent AlNi7 tetrahedra, corners with six equivalent NiAlNi2B3 tetrahedra, edges with three equivalent AlNi13 tetrahedra, edges with six NiAlNi4B3 tetrahedra, faces with three equivalent AlNi12 cuboctahedra, and faces with four NiAlNi4B3 tetrahedra. In the third Al site, Al is bonded to twelve Ni atoms to form AlNi12 cuboctahedra that share edges with twenty-four NiAlNi4B3 tetrahedra and faces with eight AlNi7 tetrahedra. There are two inequivalent B sites. In the first B site, B is bonded in a 8-coordinate geometry to eight Ni atoms. In the second B site, B is bonded in a 8-coordinate geometry to eight Ni atoms.