Materials Data on SiNiMo by Materials Project
MoNiSi crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent Mo2+ sites. In the first Mo2+ site, Mo2+ is bonded in a 7-coordinate geometry to seven Si4- atoms. There are a spread of Mo–Si bond distances ranging from 2.72–2.86 Å. In the second Mo2+ site, Mo2+ is bonded in a 5-coordinate geometry to five Si4- atoms. There are three shorter (2.70 Å) and two longer (2.80 Å) Mo–Si bond lengths. There are three inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded in a water-like geometry to two equivalent Si4- atoms. Both Ni–Si bond lengths are 2.29 Å. In the second Ni2+ site, Ni2+ is bonded in a water-like geometry to two equivalent Si4- atoms. Both Ni–Si bond lengths are 2.27 Å. In the third Ni2+ site, Ni2+ is bonded in a hexagonal planar geometry to six Si4- atoms. There are a spread of Ni–Si bond distances ranging from 2.35–2.38 Å. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded to six Mo2+, two equivalent Ni2+, and four Si4- atoms to form a mixture of edge, corner, and face-sharing SiSi4Ni2Mo6 cuboctahedra. There are a spread of Si–Si bond distances ranging from 2.39–2.56 Å. In the second Si4- site, Si4- is bonded to six Mo2+, four Ni2+, and two equivalent Si4- atoms to form distorted SiSi2Ni4Mo6 cuboctahedra that share corners with four equivalent SiSi4Ni2Mo6 cuboctahedra, edges with six equivalent SiSi2Ni4Mo6 cuboctahedra, and faces with eight SiSi4Ni2Mo6 cuboctahedra.