DOE OSTI2020
TiNi6Ga is beta Cu3Ti-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Ti is bonded to twelve Ni atoms to form TiNi12 cuboctahedra that share corners with four equivalent TiNi12 cuboctahedra, corners with eight equivalent GaNi12 cuboctahedra, edges with twenty-four NiGa4Ni8 cuboctahedra, faces with two equivalent GaNi12 cuboctahedra, faces with four equivalent TiNi12 cuboctahedra, and faces with twelve NiTi4Ni8 cuboctahedra. There are eight shorter (2.53 Å) and four longer (2.54 Å) Ti–Ni bond lengths. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded to eight equivalent Ni and four equivalent Ga atoms to form NiGa4Ni8 cuboctahedra that share corners with twelve NiGa4Ni8 cuboctahedra, edges with eight equivalent TiNi12 cuboctahedra, edges with sixteen equivalent NiTi2Ga2Ni8 cuboctahedra, faces with four equivalent GaNi12 cuboctahedra, and faces with fourteen NiGa4Ni8 cuboctahedra. All Ni–Ni bond lengths are 2.53 Å. All Ni–Ga bond lengths are 2.54 Å. In the second Ni site, Ni is bonded to four equivalent Ti and eight equivalent Ni atoms to form NiTi4Ni8 cuboctahedra that share corners with twelve NiGa4Ni8 cuboctahedra, edges with eight equivalent GaNi12 cuboctahedra, edges with sixteen equivalent NiTi2Ga2Ni8 cuboctahedra, faces with four equivalent TiNi12 cuboctahedra, and faces with fourteen NiGa4Ni8 cuboctahedra. All Ni–Ni bond lengths are 2.53 Å. In the third Ni site, Ni is bonded to two equivalent Ti, eight Ni, and two equivalent Ga atoms to form distorted NiTi2Ga2Ni8 cuboctahedra that share corners with twelve equivalent NiTi2Ga2Ni8 cuboctahedra, edges with four equivalent TiNi12 cuboctahedra, edges with four equivalent GaNi12 cuboctahedra, edges with sixteen NiGa4Ni8 cuboctahedra, faces with two equivalent TiNi12 cuboctahedra, faces with two equivalent GaNi12 cuboctahedra, and faces with fourteen NiGa4Ni8 cuboctahedra. All Ni–Ni bond lengths are 2.54 Å. Both Ni–Ga bond lengths are 2.53 Å. Ga is bonded to twelve Ni atoms to form GaNi12 cuboctahedra that share corners with four equivalent GaNi12 cuboctahedra, corners with eight equivalent TiNi12 cuboctahedra, edges with twenty-four NiTi4Ni8 cuboctahedra, faces with two equivalent TiNi12 cuboctahedra, faces with four equivalent GaNi12 cuboctahedra, and faces with twelve NiGa4Ni8 cuboctahedra.