Ta4N3 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a square co-planar geometry to two equivalent N(1) and two equivalent N(2) atoms. In the second Ta site, Ta(2) is bonded to one N(2) and four equivalent N(1) atoms to form a mixture of corner and edge-sharing TaN5 square pyramids. There are two inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Ta(1) and four equivalent Ta(2) atoms to form a mixture of corner and edge-sharing NTa6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the second N site, N(2) is bonded to two equivalent Ta(2) and four equivalent Ta(1) atoms to form a mixture of corner and edge-sharing NTa6 octahedra. The corner-sharing octahedra are not tilted.
Ta4N3 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a square co-planar geometry to two equivalent N(1) and two equivalent N(2) atoms. Both Ta(1)-N(1) bond lengths are 2.16 Å. Both Ta(1)-N(2) bond lengths are 2.20 Å. In the second Ta site, Ta(2) is bonded to one N(2) and four equivalent N(1) atoms to form a mixture of corner and edge-sharing TaN5 square pyramids. The Ta(2)-N(2) bond length is 2.27 Å. All Ta(2)-N(1) bond lengths are 2.21 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Ta(1) and four equivalent Ta(2) atoms to form a mixture of corner and edge-sharing NTa6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the second N site, N(2) is bonded to two equivalent Ta(2) and four equivalent Ta(1) atoms to form a mixture of corner and edge-sharing NTa6 octahedra. The corner-sharing octahedra are not tilted.