Materials Data on Ta4AlN3 by Materials Project

Ta4AlN3 is MAX Phase structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ta sites. In the first Ta site, Ta is bonded to six N atoms to form a mixture of edge and corner-sharing TaN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.18 Å) and three longer (2.23 Å) Ta–N bond lengths. In the second Ta site, Ta is bonded in a 3-coordinate geometry to three equivalent Al and three equivalent N atoms. All Ta–Al bond lengths are 2.83 Å. All Ta–N bond lengths are 2.20 Å. Al is bonded in a 12-coordinate geometry to six equivalent Ta atoms. There are two inequivalent N sites. In the first N site, N is bonded to six equivalent Ta 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 is bonded to six Ta atoms to form a mixture of edge and corner-sharing NTa6 octahedra. The corner-sharing octahedral tilt angles are 2°.