DOE OSTI2020
Mo2Ni3Si is Hexagonal Laves-derived structured and crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are four inequivalent Mo sites. In the first Mo site, Mo is bonded in a 12-coordinate geometry to four Mo, ten Ni, and two equivalent Si atoms. There are a spread of Mo–Mo bond distances ranging from 2.77–2.93 Å. There are a spread of Mo–Ni bond distances ranging from 2.71–2.84 Å. Both Mo–Si bond lengths are 2.76 Å. In the second Mo site, Mo is bonded in a 12-coordinate geometry to four Mo, eight Ni, and four equivalent Si atoms. There are one shorter (2.86 Å) and two longer (2.93 Å) Mo–Mo bond lengths. There are a spread of Mo–Ni bond distances ranging from 2.71–2.79 Å. There are two shorter (2.73 Å) and two longer (2.79 Å) Mo–Si bond lengths. In the third Mo site, Mo is bonded in a 12-coordinate geometry to four Mo, eight Ni, and four equivalent Si atoms. There are one shorter (2.84 Å) and two longer (2.93 Å) Mo–Mo bond lengths. There are a spread of Mo–Ni bond distances ranging from 2.71–2.79 Å. There are two shorter (2.73 Å) and two longer (2.79 Å) Mo–Si bond lengths. In the fourth Mo site, Mo is bonded in a 12-coordinate geometry to four Mo, ten Ni, and two equivalent Si atoms. The Mo–Mo bond length is 2.77 Å. There are a spread of Mo–Ni bond distances ranging from 2.71–2.84 Å. Both Mo–Si bond lengths are 2.76 Å. There are four inequivalent Ni sites. In the first Ni site, Ni is bonded to six Mo, two equivalent Ni, and four equivalent Si atoms to form NiSi4Ni2Mo6 cuboctahedra that share corners with eighteen NiSi4Ni2Mo6 cuboctahedra, edges with six NiSi4Ni2Mo6 cuboctahedra, faces with eight equivalent SiSi2Ni4Mo6 cuboctahedra, and faces with ten NiNi6Mo6 cuboctahedra. Both Ni–Ni bond lengths are 2.38 Å. There are two shorter (2.25 Å) and two longer (2.47 Å) Ni–Si bond lengths. In the second Ni site, Ni is bonded to six Mo and six Ni atoms to form NiNi6Mo6 cuboctahedra that share corners with six equivalent SiSi2Ni4Mo6 cuboctahedra, corners with twelve NiSi4Ni2Mo6 cuboctahedra, edges with two equivalent NiNi6Mo6 cuboctahedra, edges with four equivalent SiSi2Ni4Mo6 cuboctahedra, faces with two equivalent SiSi2Ni4Mo6 cuboctahedra, and faces with sixteen NiSi4Ni2Mo6 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.32–2.42 Å. In the third Ni site, Ni is bonded to six Mo and six Ni atoms to form NiNi6Mo6 cuboctahedra that share corners with eight equivalent SiSi2Ni4Mo6 cuboctahedra, corners with ten NiSi4Ni2Mo6 cuboctahedra, edges with six NiSi4Ni2Mo6 cuboctahedra, faces with four equivalent SiSi2Ni4Mo6 cuboctahedra, and faces with fourteen NiNi6Mo6 cuboctahedra. Both Ni–Ni bond lengths are 2.37 Å. In the fourth Ni site, Ni is bonded to six Mo, four Ni, and two equivalent Si atoms to form NiSi2Ni4Mo6 cuboctahedra that share corners with four equivalent SiSi2Ni4Mo6 cuboctahedra, corners with eight NiSi4Ni2Mo6 cuboctahedra, edges with six equivalent NiSi2Ni4Mo6 cuboctahedra, faces with six equivalent SiSi2Ni4Mo6 cuboctahedra, and faces with fourteen NiSi4Ni2Mo6 cuboctahedra. Both Ni–Si bond lengths are 2.27 Å. Si is bonded to six Mo, four Ni, and two equivalent Si atoms to form SiSi2Ni4Mo6 cuboctahedra that share corners with four equivalent SiSi2Ni4Mo6 cuboctahedra, corners with fourteen NiNi6Mo6 cuboctahedra, edges with two equivalent SiSi2Ni4Mo6 cuboctahedra, edges with four equivalent NiNi6Mo6 cuboctahedra, faces with four equivalent SiSi2Ni4Mo6 cuboctahedra, and faces with fourteen NiSi4Ni2Mo6 cuboctahedra. There are one shorter (2.35 Å) and one longer (2.42 Å) Si–Si bond lengths.