DOE OSTI2020
TiTaN2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Ti3+ is bonded to six N3- atoms to form TiN6 octahedra that share corners with six equivalent TiN6 octahedra, edges with four equivalent TiN6 octahedra, and edges with eight equivalent TaN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.17 Å) and four longer (2.18 Å) Ti–N bond lengths. Ta3+ is bonded to six N3- atoms to form TaN6 octahedra that share corners with six equivalent TaN6 octahedra, edges with four equivalent TaN6 octahedra, and edges with eight equivalent TiN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.17 Å) and four longer (2.18 Å) Ta–N bond lengths. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to four equivalent Ti3+ and two equivalent Ta3+ atoms to form a mixture of corner and edge-sharing NTa2Ti4 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second N3- site, N3- is bonded to two equivalent Ti3+ and four equivalent Ta3+ atoms to form NTa4Ti2 octahedra that share corners with six equivalent NTa4Ti2 octahedra and edges with twelve NTa2Ti4 octahedra. The corner-sharing octahedral tilt angles are 0°.