Materials Data on Nb6Si7Ni16 by Materials Project
Nb6Ni16Si7 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Nb2+ is bonded in a distorted square co-planar geometry to four equivalent Si4- atoms. All Nb–Si bond lengths are 2.86 Å. There are two inequivalent Ni1+ sites. In the first Ni1+ site, Ni1+ is bonded in a trigonal planar geometry to three equivalent Si4- atoms. All Ni–Si bond lengths are 2.30 Å. In the second Ni1+ site, Ni1+ is bonded to four Si4- atoms to form a mixture of edge and corner-sharing NiSi4 tetrahedra. There are one shorter (2.27 Å) and three longer (2.50 Å) Ni–Si bond lengths. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a body-centered cubic geometry to eight equivalent Ni1+ atoms. In the second Si4- site, Si4- is bonded to four equivalent Nb2+ and eight Ni1+ atoms to form a mixture of face and corner-sharing SiNb4Ni8 cuboctahedra.