DOE OSTI2020
Ti3Ni12Al is Uranium Silicide-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. there are two inequivalent Ti sites. In the first Ti site, Ti is bonded to twelve Ni atoms to form TiNi12 cuboctahedra that share corners with six equivalent TiNi12 cuboctahedra, corners with six equivalent AlNi12 cuboctahedra, edges with twenty-four NiTi2Al2Ni8 cuboctahedra, faces with six equivalent TiNi12 cuboctahedra, and faces with twelve NiTi4Ni8 cuboctahedra. All Ti–Ni bond lengths are 2.54 Å. In the second Ti site, Ti is bonded to twelve Ni atoms to form TiNi12 cuboctahedra that share corners with six equivalent TiNi12 cuboctahedra, corners with twelve NiTi3AlNi8 cuboctahedra, edges with eighteen NiTi2Al2Ni8 cuboctahedra, faces with three equivalent AlNi12 cuboctahedra, faces with five TiNi12 cuboctahedra, and faces with twelve NiTi2Al2Ni8 cuboctahedra. There are a spread of Ti–Ni bond distances ranging from 2.54–2.57 Å. There are six inequivalent Ni sites. In the first Ni site, Ni is bonded to two equivalent Ti, eight Ni, and two equivalent Al atoms to form distorted NiTi2Al2Ni8 cuboctahedra that share corners with twelve NiTi2Al2Ni8 cuboctahedra, edges with two equivalent AlNi12 cuboctahedra, edges with six TiNi12 cuboctahedra, edges with sixteen NiTi2Al2Ni8 cuboctahedra, faces with two equivalent TiNi12 cuboctahedra, faces with two equivalent AlNi12 cuboctahedra, and faces with fourteen NiTi2Al2Ni8 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.47–2.61 Å. Both Ni–Al bond lengths are 2.54 Å. In the second Ni site, Ni is bonded to two equivalent Ti, eight Ni, and two equivalent Al atoms to form distorted NiTi2Al2Ni8 cuboctahedra that share corners with twelve NiTi4Ni8 cuboctahedra, edges with two equivalent AlNi12 cuboctahedra, edges with six TiNi12 cuboctahedra, edges with sixteen NiTi2Al2Ni8 cuboctahedra, faces with two equivalent TiNi12 cuboctahedra, faces with two equivalent AlNi12 cuboctahedra, and faces with fourteen NiTi2Al2Ni8 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.47–2.61 Å. Both Ni–Al bond lengths are 2.54 Å. In the third Ni site, Ni is bonded to four Ti and eight Ni atoms to form distorted NiTi4Ni8 cuboctahedra that share corners with twelve NiTi2Al2Ni8 cuboctahedra, edges with two equivalent AlNi12 cuboctahedra, edges with six TiNi12 cuboctahedra, edges with sixteen NiTi2Al2Ni8 cuboctahedra, faces with four TiNi12 cuboctahedra, and faces with fourteen NiTi4Ni8 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.46–2.62 Å. In the fourth Ni site, Ni is bonded to four Ti and eight Ni atoms to form distorted NiTi4Ni8 cuboctahedra that share corners with twelve NiTi4Ni8 cuboctahedra, edges with two equivalent AlNi12 cuboctahedra, edges with six TiNi12 cuboctahedra, edges with sixteen NiTi2Al2Ni8 cuboctahedra, faces with four TiNi12 cuboctahedra, and faces with fourteen NiTi4Ni8 cuboctahedra. All Ni–Ni bond lengths are 2.52 Å. In the fifth Ni site, Ni is bonded to three Ti, eight Ni, and one Al atom to form NiTi3AlNi8 cuboctahedra that share corners with four equivalent TiNi12 cuboctahedra, corners with fourteen NiTi3AlNi8 cuboctahedra, edges with two equivalent AlNi12 cuboctahedra, edges with four TiNi12 cuboctahedra, edges with twelve NiTi2Al2Ni8 cuboctahedra, a faceface with one AlNi12 cuboctahedra, faces with three TiNi12 cuboctahedra, and faces with sixteen NiTi2Al2Ni8 cuboctahedra. There are two shorter (2.53 Å) and two longer (2.54 Å) Ni–Ni bond lengths. The Ni–Al bond length is 2.53 Å. In the sixth Ni site, Ni is bonded to three Ti, eight Ni, and one Al atom to form NiTi3AlNi8 cuboctahedra that share corners with four equivalent TiNi12 cuboctahedra, corners with fourteen NiTi3AlNi8 cuboctahedra, edges with two equivalent AlNi12 cuboctahedra, edges with four TiNi12 cuboctahedra, edges with twelve NiTi2Al2Ni8 cuboctahedra, a faceface with one AlNi12 cuboctahedra, faces with three TiNi12 cuboctahedra, and faces with sixteen NiTi2Al2Ni8 cuboctahedra. The Ni–Ni bond length is 2.52 Å. The Ni–Al bond length is 2.53 Å. Al is bonded to twelve Ni atoms to form AlNi12 cuboctahedra that share corners with six equivalent TiNi12 cuboctahedra, corners with six equivalent AlNi12 cuboctahedra, edges with twenty-four NiTi2Al2Ni8 cuboctahedra, faces with six equivalent TiNi12 cuboctahedra, and faces with twelve NiTi2Al2Ni8 cuboctahedra.