Ta3N5 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 8-coordinate geometry to one N(2), two equivalent N(3), two equivalent N(4), and three equivalent N(1) atoms. In the second Ta site, Ta(2) is bonded in a 8-coordinate geometry to one N(3), two equivalent N(2), two equivalent N(4), and three equivalent N(5) atoms. In the third Ta site, Ta(3) is bonded in a 8-coordinate geometry to one N(2), one N(4), two equivalent N(1), two equivalent N(3), and two equivalent N(5) atoms. There are five inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Ta(3) and three equivalent Ta(1) atoms to form distorted NTa5 trigonal bipyramids that share  a cornercorner with one N(2)Ta4 tetrahedra, corners with two equivalent N(4)Ta5 trigonal bipyramids, corners with two equivalent N(5)Ta5 trigonal bipyramids, corners with six equivalent N(3)Ta5 trigonal bipyramids, edges with two equivalent N(2)Ta4 tetrahedra,  an edgeedge with one N(5)Ta5 trigonal bipyramid, edges with two equivalent N(3)Ta5 trigonal bipyramids, edges with three equivalent N(4)Ta5 trigonal bipyramids, and edges with four equivalent N(1)Ta5 trigonal bipyramids. In the second N site, N(2) is bonded to one Ta(1), one Ta(3), and two equivalent Ta(2) atoms to form distorted NTa4 tetrahedra that share corners with two equivalent N(2)Ta4 tetrahedra,  a cornercorner with one N(1)Ta5 trigonal bipyramid, corners with two equivalent N(3)Ta5 trigonal bipyramids, corners with two equivalent N(5)Ta5 trigonal bipyramids, corners with five equivalent N(4)Ta5 trigonal bipyramids,  an edgeedge with one N(4)Ta5 trigonal bipyramid, edges with two equivalent N(1)Ta5 trigonal bipyramids, edges with two equivalent N(3)Ta5 trigonal bipyramids, and edges with three equivalent N(5)Ta5 trigonal bipyramids. In the third N site, N(3) is bonded to one Ta(2), two equivalent Ta(1), and two equivalent Ta(3) atoms to form distorted NTa5 trigonal bipyramids that share corners with two equivalent N(2)Ta4 tetrahedra, corners with two equivalent N(4)Ta5 trigonal bipyramids, corners with five equivalent N(5)Ta5 trigonal bipyramids, corners with six equivalent N(1)Ta5 trigonal bipyramids, edges with two equivalent N(2)Ta4 tetrahedra,  an edgeedge with one N(5)Ta5 trigonal bipyramid, edges with two equivalent N(1)Ta5 trigonal bipyramids, edges with two equivalent N(3)Ta5 trigonal bipyramids, and edges with three equivalent N(4)Ta5 trigonal bipyramids. In the fourth N site, N(4) is bonded to one Ta(3), two equivalent Ta(1), and two equivalent Ta(2) atoms to form distorted NTa5 trigonal bipyramids that share corners with five equivalent N(2)Ta4 tetrahedra, corners with two equivalent N(1)Ta5 trigonal bipyramids, corners with two equivalent N(3)Ta5 trigonal bipyramids, corners with six equivalent N(5)Ta5 trigonal bipyramids,  an edgeedge with one N(2)Ta4 tetrahedra,  an edgeedge with one N(5)Ta5 trigonal bipyramid, edges with two equivalent N(4)Ta5 trigonal bipyramids, edges with three equivalent N(1)Ta5 trigonal bipyramids, and edges with three equivalent N(3)Ta5 trigonal bipyramids. In the fifth N site, N(5) is bonded to two equivalent Ta(3) and three equivalent Ta(2) atoms to form distorted NTa5 trigonal bipyramids that share corners with two equivalent N(2)Ta4 tetrahedra, corners with two equivalent N(1)Ta5 trigonal bipyramids, corners with five equivalent N(3)Ta5 trigonal bipyramids, corners with six equivalent N(4)Ta5 trigonal bipyramids, edges with three equivalent N(2)Ta4 tetrahedra,  an edgeedge with one N(1)Ta5 trigonal bipyramid,  an edgeedge with one N(3)Ta5 trigonal bipyramid,  an edgeedge with one N(4)Ta5 trigonal bipyramid, and edges with four equivalent N(5)Ta5 trigonal bipyramids.
Ta3N5 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 8-coordinate geometry to one N(2), two equivalent N(3), two equivalent N(4), and three equivalent N(1) atoms. The Ta(1)-N(2) bond length is 2.06 Å. Both Ta(1)-N(3) bond lengths are 2.31 Å. Both Ta(1)-N(4) bond lengths are 2.21 Å. All Ta(1)-N(1) bond lengths are 2.23 Å. In the second Ta site, Ta(2) is bonded in a 8-coordinate geometry to one N(3), two equivalent N(2), two equivalent N(4), and three equivalent N(5) atoms. The Ta(2)-N(3) bond length is 2.24 Å. Both Ta(2)-N(2) bond lengths are 2.05 Å. Both Ta(2)-N(4) bond lengths are 2.25 Å. There are two shorter (2.21 Å) and one longer (2.28 Å) Ta(2)-N(5) bond length. In the third Ta site, Ta(3) is bonded in a 8-coordinate geometry to one N(2), one N(4), two equivalent N(1), two equivalent N(3), and two equivalent N(5) atoms. The Ta(3)-N(2) bond length is 2.08 Å. The Ta(3)-N(4) bond length is 2.25 Å. Both Ta(3)-N(1) bond lengths are 2.25 Å. Both Ta(3)-N(3) bond lengths are 2.19 Å. Both Ta(3)-N(5) bond lengths are 2.25 Å. There are five inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Ta(3) and three equivalent Ta(1) atoms to form distorted NTa5 trigonal bipyramids that share  a cornercorner with one N(2)Ta4 tetrahedra, corners with two equivalent N(4)Ta5 trigonal bipyramids, corners with two equivalent N(5)Ta5 trigonal bipyramids, corners with six equivalent N(3)Ta5 trigonal bipyramids, edges with two equivalent N(2)Ta4 tetrahedra,  an edgeedge with one N(5)Ta5 trigonal bipyramid, edges with two equivalent N(3)Ta5 trigonal bipyramids, edges with three equivalent N(4)Ta5 trigonal bipyramids, and edges with four equivalent N(1)Ta5 trigonal bipyramids. In the second N site, N(2) is bonded to one Ta(1), one Ta(3), and two equivalent Ta(2) atoms to form distorted NTa4 tetrahedra that share corners with two equivalent N(2)Ta4 tetrahedra,  a cornercorner with one N(1)Ta5 trigonal bipyramid, corners with two equivalent N(3)Ta5 trigonal bipyramids, corners with two equivalent N(5)Ta5 trigonal bipyramids, corners with five equivalent N(4)Ta5 trigonal bipyramids,  an edgeedge with one N(4)Ta5 trigonal bipyramid, edges with two equivalent N(1)Ta5 trigonal bipyramids, edges with two equivalent N(3)Ta5 trigonal bipyramids, and edges with three equivalent N(5)Ta5 trigonal bipyramids. In the third N site, N(3) is bonded to one Ta(2), two equivalent Ta(1), and two equivalent Ta(3) atoms to form distorted NTa5 trigonal bipyramids that share corners with two equivalent N(2)Ta4 tetrahedra, corners with two equivalent N(4)Ta5 trigonal bipyramids, corners with five equivalent N(5)Ta5 trigonal bipyramids, corners with six equivalent N(1)Ta5 trigonal bipyramids, edges with two equivalent N(2)Ta4 tetrahedra,  an edgeedge with one N(5)Ta5 trigonal bipyramid, edges with two equivalent N(1)Ta5 trigonal bipyramids, edges with two equivalent N(3)Ta5 trigonal bipyramids, and edges with three equivalent N(4)Ta5 trigonal bipyramids. In the fourth N site, N(4) is bonded to one Ta(3), two equivalent Ta(1), and two equivalent Ta(2) atoms to form distorted NTa5 trigonal bipyramids that share corners with five equivalent N(2)Ta4 tetrahedra, corners with two equivalent N(1)Ta5 trigonal bipyramids, corners with two equivalent N(3)Ta5 trigonal bipyramids, corners with six equivalent N(5)Ta5 trigonal bipyramids,  an edgeedge with one N(2)Ta4 tetrahedra,  an edgeedge with one N(5)Ta5 trigonal bipyramid, edges with two equivalent N(4)Ta5 trigonal bipyramids, edges with three equivalent N(1)Ta5 trigonal bipyramids, and edges with three equivalent N(3)Ta5 trigonal bipyramids. In the fifth N site, N(5) is bonded to two equivalent Ta(3) and three equivalent Ta(2) atoms to form distorted NTa5 trigonal bipyramids that share corners with two equivalent N(2)Ta4 tetrahedra, corners with two equivalent N(1)Ta5 trigonal bipyramids, corners with five equivalent N(3)Ta5 trigonal bipyramids, corners with six equivalent N(4)Ta5 trigonal bipyramids, edges with three equivalent N(2)Ta4 tetrahedra,  an edgeedge with one N(1)Ta5 trigonal bipyramid,  an edgeedge with one N(3)Ta5 trigonal bipyramid,  an edgeedge with one N(4)Ta5 trigonal bipyramid, and edges with four equivalent N(5)Ta5 trigonal bipyramids.