Materials Data on Nb32N27 by Materials Project
(Nb4N3)2(Nb3N2)2Nb18N17 crystallizes in the trigonal R-3m space group. The structure is two-dimensional and consists of three Nb18N17 sheets oriented in the (0, 0, 1) direction; six Nb3N2 sheets oriented in the (0, 0, 1) direction; and six Nb4N3 sheets oriented in the (0, 0, 1) direction. In each Nb18N17 sheet, there are eight inequivalent Nb+2.53+ sites. In the first Nb+2.53+ site, Nb+2.53+ is bonded in a distorted T-shaped geometry to three equivalent N3- atoms. All Nb–N bond lengths are 2.20 Å. In the second Nb+2.53+ site, Nb+2.53+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing NbN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.21 Å) and three longer (2.23 Å) Nb–N bond lengths. In the third Nb+2.53+ site, Nb+2.53+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing NbN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.22 Å) and three longer (2.23 Å) Nb–N bond lengths. In the fourth Nb+2.53+ site, Nb+2.53+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing NbN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.21 Å) and three longer (2.22 Å) Nb–N bond lengths. In the fifth Nb+2.53+ site, Nb+2.53+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing NbN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.21 Å) and three longer (2.22 Å) Nb–N bond lengths. In the sixth Nb+2.53+ site, Nb+2.53+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing NbN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.21 Å) and three longer (2.22 Å) Nb–N bond lengths. In the seventh Nb+2.53+ site, Nb+2.53+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing NbN6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Nb–N bond lengths are 2.22 Å. In the eighth Nb+2.53+ site, Nb+2.53+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing NbN6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Nb–N bond lengths are 2.22 Å. There are nine inequivalent N3- sites. In the first N3- site, N3- is bonded to six Nb+2.53+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second N3- site, N3- is bonded to six Nb+2.53+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the third N3- site, N3- is bonded to six Nb+2.53+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourth N3- site, N3- is bonded to six Nb+2.53+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifth N3- site, N3- is bonded to six Nb+2.53+ 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+2.53+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the seventh N3- site, N3- is bonded to six Nb+2.53+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 0°. All N–Nb bond lengths are 2.21 Å. In the eighth N3- site, N3- is bonded to six Nb+2.53+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 0°. All N–Nb bond lengths are 2.22 Å. In the ninth N3- site, N3- is bonded to six equivalent Nb+2.53+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 0°. In each Nb3N2 sheet, there are three inequivalent Nb+2.53+ sites. In the first Nb+2.53+ site, Nb+2.53+ is bonded in a distorted T-shaped geometry to three equivalent N3- atoms. All Nb–N bond lengths are 2.20 Å. In the second Nb+2.53+ site, Nb+2.53+ is bonded to six N3- atoms to form edge-sharing NbN6 octahedra. All Nb–N bond lengths are 2.23 Å. In the third Nb+2.53+ site, Nb+2.53+ is bonded in a distorted T-shaped geometry to three equivalent N3- atoms. All Nb–N bond lengths are 2.20 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to six Nb+2.53+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second N3- site, N3- is bonded to six Nb+2.53+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 0°. In each Nb4N3 sheet, there are four inequivalent Nb+2.53+ sites. In the first Nb+2.53+ site, Nb+2.53+ is bonded in a distorted T-shaped geometry to three equivalent N3- atoms. All Nb–N bond lengths are 2.21 Å. In the second Nb+2.53+ site, Nb+2.53+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing NbN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.22 Å) and three longer (2.24 Å) Nb–N bond lengths. In the third Nb+2.53+ site, Nb+2.53+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing NbN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.22 Å) and three longer (2.24 Å) Nb–N bond lengths. In the fourth Nb+2.53+ site, Nb+2.53+ is bonded in a distorted T-shaped geometry to three equivalent N3- atoms. All Nb–N bond lengths are 2.21 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to six Nb+2.53+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second N3- site, N3- is bonded to six Nb+2.53+ atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 1°.