Ta4AlN3 is MAX Phase structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to three equivalent N(1) and three equivalent N(2) atoms to form a mixture of edge and corner-sharing TaN6 octahedra. The corner-sharing octahedra are not tilted. In the second Ta site, Ta(2) is bonded in a 3-coordinate geometry to three equivalent Al(1) and three equivalent N(2) atoms. Al(1) is bonded in a 6-coordinate geometry to six equivalent Ta(2) atoms. There are two inequivalent N sites. In the first N site, N(1) is bonded to six equivalent Ta(1) atoms to form a mixture of edge and corner-sharing NTa6 octahedra. The corner-sharing octahedral tilt angles are 2°. In the second N site, N(2) is bonded to three equivalent Ta(1) and three equivalent Ta(2) atoms to form a mixture of edge and corner-sharing NTa6 octahedra. The corner-sharing octahedral tilt angles are 2°.
Ta4AlN3 is MAX Phase structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to three equivalent N(1) and three equivalent N(2) atoms to form a mixture of edge and corner-sharing TaN6 octahedra. The corner-sharing octahedra are not tilted. All Ta(1)-N(1) bond lengths are 2.18 Å. All Ta(1)-N(2) bond lengths are 2.23 Å. In the second Ta site, Ta(2) is bonded in a 3-coordinate geometry to three equivalent Al(1) and three equivalent N(2) atoms. All Ta(2)-Al(1) bond lengths are 2.83 Å. All Ta(2)-N(2) bond lengths are 2.20 Å. Al(1) is bonded in a 6-coordinate geometry to six equivalent Ta(2) atoms. There are two inequivalent N sites. In the first N site, N(1) is bonded to six equivalent Ta(1) atoms to form a mixture of edge and corner-sharing NTa6 octahedra. The corner-sharing octahedral tilt angles are 2°. In the second N site, N(2) is bonded to three equivalent Ta(1) and three equivalent Ta(2) atoms to form a mixture of edge and corner-sharing NTa6 octahedra. The corner-sharing octahedral tilt angles are 2°.