Nb16N13 crystallizes in the orthorhombic Immm space group. There are five inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a square co-planar geometry to one N(1), one N(3), and two equivalent N(2) atoms. In the second Nb site, Nb(2) is bonded to one N(5) and four equivalent N(2) atoms to form NbN5 square pyramids that share  a cornercorner with one Nb(2)N5 square pyramid, corners with four equivalent Nb(3)N5 square pyramids, edges with two equivalent Nb(5)N6 octahedra, edges with two equivalent Nb(3)N5 square pyramids, and edges with four equivalent Nb(4)N5 square pyramids. In the third Nb site, Nb(3) is bonded to one N(3) and four equivalent N(2) atoms to form NbN5 square pyramids that share corners with two equivalent Nb(5)N6 octahedra,  a cornercorner with one Nb(3)N5 square pyramid, corners with two equivalent Nb(2)N5 square pyramids, corners with two equivalent Nb(4)N5 square pyramids,  an edgeedge with one Nb(5)N6 octahedra,  an edgeedge with one Nb(2)N5 square pyramid, edges with two equivalent Nb(3)N5 square pyramids, and edges with two equivalent Nb(4)N5 square pyramids. The corner-sharing octahedral tilt angles are 2°. In the fourth Nb site, Nb(4) is bonded to one N(3), one N(4), one N(5), and two equivalent N(2) atoms to form NbN5 square pyramids that share corners with two equivalent Nb(3)N5 square pyramids, corners with three equivalent Nb(4)N5 square pyramids, edges with two equivalent Nb(5)N6 octahedra, edges with two equivalent Nb(2)N5 square pyramids, edges with two equivalent Nb(3)N5 square pyramids, and edges with two equivalent Nb(4)N5 square pyramids. In the fifth Nb site, Nb(5) is bonded to one N(1), one N(4), and four equivalent N(2) atoms to form NbN6 octahedra that share corners with two equivalent Nb(5)N6 octahedra, corners with four equivalent Nb(3)N5 square pyramids, edges with two equivalent Nb(2)N5 square pyramids, edges with two equivalent Nb(3)N5 square pyramids, and edges with four equivalent Nb(4)N5 square pyramids. The corner-sharing octahedra are not tilted. There are five inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Nb(5) and four equivalent Nb(1) atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second N site, N(2) is bonded to one Nb(1), one Nb(2), one Nb(4), one Nb(5), and two equivalent Nb(3) atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the third N site, N(3) is bonded to two equivalent Nb(1), two equivalent Nb(3), and two equivalent Nb(4) atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles range from 1-5°. In the fourth N site, N(4) is bonded to two equivalent Nb(5) and four equivalent Nb(4) atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedra are not tilted. In the fifth N site, N(5) is bonded to two equivalent Nb(2) and four equivalent Nb(4) atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 5°.
Nb16N13 crystallizes in the orthorhombic Immm space group. There are five inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a square co-planar geometry to one N(1), one N(3), and two equivalent N(2) atoms. The Nb(1)-N(1) bond length is 2.23 Å. The Nb(1)-N(3) bond length is 2.20 Å. Both Nb(1)-N(2) bond lengths are 2.19 Å. In the second Nb site, Nb(2) is bonded to one N(5) and four equivalent N(2) atoms to form NbN5 square pyramids that share  a cornercorner with one Nb(2)N5 square pyramid, corners with four equivalent Nb(3)N5 square pyramids, edges with two equivalent Nb(5)N6 octahedra, edges with two equivalent Nb(3)N5 square pyramids, and edges with four equivalent Nb(4)N5 square pyramids. The Nb(2)-N(5) bond length is 2.25 Å. All Nb(2)-N(2) bond lengths are 2.21 Å. In the third Nb site, Nb(3) is bonded to one N(3) and four equivalent N(2) atoms to form NbN5 square pyramids that share corners with two equivalent Nb(5)N6 octahedra,  a cornercorner with one Nb(3)N5 square pyramid, corners with two equivalent Nb(2)N5 square pyramids, corners with two equivalent Nb(4)N5 square pyramids,  an edgeedge with one Nb(5)N6 octahedra,  an edgeedge with one Nb(2)N5 square pyramid, edges with two equivalent Nb(3)N5 square pyramids, and edges with two equivalent Nb(4)N5 square pyramids. The corner-sharing octahedral tilt angles are 2°. The Nb(3)-N(3) bond length is 2.28 Å. All Nb(3)-N(2) bond lengths are 2.22 Å. In the fourth Nb site, Nb(4) is bonded to one N(3), one N(4), one N(5), and two equivalent N(2) atoms to form NbN5 square pyramids that share corners with two equivalent Nb(3)N5 square pyramids, corners with three equivalent Nb(4)N5 square pyramids, edges with two equivalent Nb(5)N6 octahedra, edges with two equivalent Nb(2)N5 square pyramids, edges with two equivalent Nb(3)N5 square pyramids, and edges with two equivalent Nb(4)N5 square pyramids. The Nb(4)-N(3) bond length is 2.22 Å. The Nb(4)-N(4) bond length is 2.30 Å. The Nb(4)-N(5) bond length is 2.21 Å. Both Nb(4)-N(2) bond lengths are 2.19 Å. In the fifth Nb site, Nb(5) is bonded to one N(1), one N(4), and four equivalent N(2) atoms to form NbN6 octahedra that share corners with two equivalent Nb(5)N6 octahedra, corners with four equivalent Nb(3)N5 square pyramids, edges with two equivalent Nb(2)N5 square pyramids, edges with two equivalent Nb(3)N5 square pyramids, and edges with four equivalent Nb(4)N5 square pyramids. The corner-sharing octahedra are not tilted. The Nb(5)-N(1) bond length is 2.18 Å. The Nb(5)-N(4) bond length is 2.20 Å. All Nb(5)-N(2) bond lengths are 2.22 Å. There are five inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Nb(5) and four equivalent Nb(1) atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second N site, N(2) is bonded to one Nb(1), one Nb(2), one Nb(4), one Nb(5), and two equivalent Nb(3) atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the third N site, N(3) is bonded to two equivalent Nb(1), two equivalent Nb(3), and two equivalent Nb(4) atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles range from 1-5°. In the fourth N site, N(4) is bonded to two equivalent Nb(5) and four equivalent Nb(4) atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedra are not tilted. In the fifth N site, N(5) is bonded to two equivalent Nb(2) and four equivalent Nb(4) atoms to form a mixture of edge and corner-sharing NNb6 octahedra. The corner-sharing octahedral tilt angles are 5°.