Materials Data on Nb6Co16Si7 by Materials Project
Nb6Co16Si7 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 2.85 Å. There are two inequivalent Co1+ sites. In the first Co1+ site, Co1+ is bonded to four Si4- atoms to form a mixture of corner and edge-sharing CoSi4 tetrahedra. There are one shorter (2.30 Å) and three longer (2.47 Å) Co–Si bond lengths. In the second Co1+ site, Co1+ is bonded in a trigonal planar geometry to three equivalent Si4- atoms. All Co–Si bond lengths are 2.29 Å. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded to four equivalent Nb2+ and eight Co1+ atoms to form a mixture of corner and face-sharing SiNb4Co8 cuboctahedra. In the second Si4- site, Si4- is bonded in a body-centered cubic geometry to eight equivalent Co1+ atoms.