Materials Data on Ti19N25 by Materials Project

(Ti2N3)2(TiN2)3Ti12N13 crystallizes in the trigonal R-3m space group. The structure is two-dimensional and consists of three Ti12N13 sheets oriented in the (0, 0, 1) direction; six Ti2N3 sheets oriented in the (0, 0, 1) direction; and nine TiN2 sheets oriented in the (0, 0, 1) direction. In each Ti12N13 sheet, there are six inequivalent Ti+3.95+ sites. In the first Ti+3.95+ site, Ti+3.95+ is bonded to six N3- atoms to form a mixture of distorted edge and corner-sharing TiN6 octahedra. The corner-sharing octahedral tilt angles are 9°. There are three shorter (1.90 Å) and three longer (2.35 Å) Ti–N bond lengths. In the second Ti+3.95+ site, Ti+3.95+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing TiN6 octahedra. The corner-sharing octahedra tilt angles range from 0–9°. There are three shorter (2.08 Å) and three longer (2.15 Å) Ti–N bond lengths. In the third Ti+3.95+ site, Ti+3.95+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing TiN6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ti–N bond lengths are 2.14 Å. In the fourth Ti+3.95+ site, Ti+3.95+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing TiN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.13 Å) and three longer (2.14 Å) Ti–N bond lengths. In the fifth Ti+3.95+ site, Ti+3.95+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing TiN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.13 Å) and three longer (2.14 Å) Ti–N bond lengths. In the sixth Ti+3.95+ site, Ti+3.95+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing TiN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.13 Å) and three longer (2.14 Å) Ti–N bond lengths. There are seven inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal non-coplanar geometry to three equivalent Ti+3.95+ atoms. In the second N3- site, N3- is bonded to six Ti+3.95+ atoms to form a mixture of edge and corner-sharing NTi6 octahedra. The corner-sharing octahedral tilt angles are 3°. In the third N3- site, N3- is bonded to six Ti+3.95+ atoms to form a mixture of edge and corner-sharing NTi6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the fourth N3- site, N3- is bonded to six Ti+3.95+ atoms to form a mixture of edge and corner-sharing NTi6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifth N3- site, N3- is bonded to six Ti+3.95+ atoms to form a mixture of edge and corner-sharing NTi6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the sixth N3- site, N3- is bonded to six Ti+3.95+ atoms to form a mixture of edge and corner-sharing NTi6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the seventh N3- site, N3- is bonded to six equivalent Ti+3.95+ atoms to form a mixture of edge and corner-sharing NTi6 octahedra. The corner-sharing octahedral tilt angles are 0°. In each Ti2N3 sheet, Ti+3.95+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing TiN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (1.95 Å) and three longer (2.21 Å) Ti–N bond lengths. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal non-coplanar geometry to three equivalent Ti+3.95+ atoms. In the second N3- site, N3- is bonded to six equivalent Ti+3.95+ atoms to form edge-sharing NTi6 octahedra. In the third N3- site, N3- is bonded in a trigonal non-coplanar geometry to three equivalent Ti+3.95+ atoms. All N–Ti bond lengths are 1.95 Å. In each TiN2 sheet, Ti+3.95+ is bonded to six N3- atoms to form edge-sharing TiN6 octahedra. There are three shorter (2.00 Å) and three longer (2.01 Å) Ti–N bond lengths. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Ti+3.95+ atoms. In the second N3- site, N3- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Ti+3.95+ atoms.