Materials Data on Nb8N5 by Materials Project
Nb8N5 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are four inequivalent Nb sites. In the first Nb site, Nb is bonded in a rectangular see-saw-like geometry to four equivalent N atoms. All Nb–N bond lengths are 2.19 Å. In the second Nb site, Nb is bonded to five N atoms to form corner-sharing NbN5 square pyramids. There are four shorter (2.19 Å) and one longer (2.21 Å) Nb–N bond lengths. In the third Nb site, Nb is bonded in a linear geometry to two equivalent N atoms. Both Nb–N bond lengths are 2.20 Å. In the fourth Nb site, Nb is bonded in a square co-planar geometry to four N atoms. All Nb–N bond lengths are 2.19 Å. There are two inequivalent N sites. In the first N site, N is bonded to six Nb atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second N site, N is bonded to six Nb atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 0°.