DOE OSTI2020
TiNi2Cu is beta Cu3Ti-derived structured and crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. Ti is bonded to eight equivalent Ni and four equivalent Cu atoms to form TiCu4Ni8 cuboctahedra that share corners with two equivalent TiCu4Ni8 cuboctahedra, corners with eight equivalent NiTi4Cu4Ni4 cuboctahedra, corners with eight equivalent CuTi4Ni8 cuboctahedra, edges with six equivalent TiCu4Ni8 cuboctahedra, edges with twelve equivalent NiTi4Cu4Ni4 cuboctahedra, faces with six equivalent TiCu4Ni8 cuboctahedra, faces with six equivalent CuTi4Ni8 cuboctahedra, and faces with eight equivalent NiTi4Cu4Ni4 cuboctahedra. There are two shorter (2.55 Å) and six longer (2.58 Å) Ti–Ni bond lengths. There are two shorter (2.59 Å) and two longer (2.64 Å) Ti–Cu bond lengths. Ni is bonded to four equivalent Ti, four equivalent Ni, and four equivalent Cu atoms to form distorted NiTi4Cu4Ni4 cuboctahedra that share corners with four equivalent TiCu4Ni8 cuboctahedra, corners with four equivalent CuTi4Ni8 cuboctahedra, corners with ten equivalent NiTi4Cu4Ni4 cuboctahedra, edges with six equivalent TiCu4Ni8 cuboctahedra, edges with six equivalent NiTi4Cu4Ni4 cuboctahedra, edges with six equivalent CuTi4Ni8 cuboctahedra, faces with four equivalent TiCu4Ni8 cuboctahedra, faces with four equivalent CuTi4Ni8 cuboctahedra, and faces with twelve equivalent NiTi4Cu4Ni4 cuboctahedra. There are one shorter (2.58 Å) and three longer (2.60 Å) Ni–Ni bond lengths. There are a spread of Ni–Cu bond distances ranging from 2.50–2.63 Å. Cu is bonded to four equivalent Ti and eight equivalent Ni atoms to form CuTi4Ni8 cuboctahedra that share corners with two equivalent CuTi4Ni8 cuboctahedra, corners with eight equivalent TiCu4Ni8 cuboctahedra, corners with eight equivalent NiTi4Cu4Ni4 cuboctahedra, edges with six equivalent CuTi4Ni8 cuboctahedra, edges with twelve equivalent NiTi4Cu4Ni4 cuboctahedra, faces with six equivalent TiCu4Ni8 cuboctahedra, faces with six equivalent CuTi4Ni8 cuboctahedra, and faces with eight equivalent NiTi4Cu4Ni4 cuboctahedra.