Materials Data on Nb16N13 by Materials Project
Nb16N13 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are five inequivalent Nb+2.44+ sites. In the first Nb+2.44+ site, Nb+2.44+ is bonded in a rectangular see-saw-like geometry to four N3- atoms. There are a spread of Nb–N bond distances ranging from 2.18–2.23 Å. In the second Nb+2.44+ site, Nb+2.44+ is bonded to five N3- atoms to form NbN5 square pyramids that share corners with five NbN5 square pyramids, edges with two equivalent NbN6 octahedra, and edges with six NbN5 square pyramids. There are four shorter (2.22 Å) and one longer (2.25 Å) Nb–N bond lengths. In the third Nb+2.44+ site, Nb+2.44+ is bonded to five N3- atoms to form NbN5 square pyramids that share corners with two equivalent NbN6 octahedra, corners with five NbN5 square pyramids, an edgeedge with one NbN6 octahedra, and edges with five NbN5 square pyramids. The corner-sharing octahedral tilt angles are 2°. There are a spread of Nb–N bond distances ranging from 2.21–2.28 Å. In the fourth Nb+2.44+ site, Nb+2.44+ is bonded to five N3- atoms to form NbN5 square pyramids that share corners with five NbN5 square pyramids, edges with two equivalent NbN6 octahedra, and edges with six NbN5 square pyramids. There are a spread of Nb–N bond distances ranging from 2.19–2.30 Å. In the fifth Nb+2.44+ site, Nb+2.44+ is bonded to six N3- atoms to form NbN6 octahedra that share corners with two equivalent NbN6 octahedra, corners with four equivalent NbN5 square pyramids, and edges with eight NbN5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–N bond distances ranging from 2.18–2.22 Å. There are six inequivalent N3- sites. In the first N3- site, N3- is bonded to six Nb+2.44+ 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 N3- site, N3- is bonded to six Nb+2.44+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedra tilt angles range from 1–5°. In the third N3- site, N3- is bonded to six Nb+2.44+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedra tilt angles range from 1–5°. In the fourth N3- site, N3- is bonded to six Nb+2.44+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedra tilt angles range from 1–5°. In the fifth N3- site, N3- is bonded to six Nb+2.44+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the sixth N3- site, N3- is bonded to six Nb+2.44+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 5°.