Sr3Bi3N5 crystallizes in the triclinic P-1 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 4-coordinate geometry to one N(3), one N(4), and two equivalent N(2) atoms. In the second Sr site, Sr(2) is bonded in a 5-coordinate geometry to one N(1), one N(3), one N(4), and two equivalent N(5) atoms. In the third Sr site, Sr(3) is bonded in a 4-coordinate geometry to one N(1), one N(2), one N(3), and one N(4) atom. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a distorted trigonal non-coplanar geometry to one N(1), one N(3), and one N(5) atom. In the second Bi site, Bi(2) is bonded in a distorted trigonal non-coplanar geometry to one N(1), one N(2), and one N(4) atom. In the third Bi site, Bi(3) is bonded in a 3-coordinate geometry to one N(1), one N(4), and one N(5) atom. There are five inequivalent N sites. In the first N site, N(1) is bonded to one Sr(2), one Sr(3), one Bi(1), one Bi(2), and one Bi(3) atom to form NSr2Bi3 trigonal bipyramids that share corners with two equivalent N(2)Sr3Bi tetrahedra, corners with three equivalent N(3)Sr3Bi tetrahedra, corners with two equivalent N(5)Sr2Bi2 trigonal pyramids, edges with two equivalent N(4)Sr3Bi2 trigonal bipyramids, and  an edgeedge with one N(5)Sr2Bi2 trigonal pyramid. In the second N site, N(2) is bonded to one Sr(3), two equivalent Sr(1), and one Bi(2) atom to form distorted NSr3Bi tetrahedra that share corners with three equivalent N(3)Sr3Bi tetrahedra, corners with two equivalent N(1)Sr2Bi3 trigonal bipyramids, corners with four equivalent N(4)Sr3Bi2 trigonal bipyramids, and  an edgeedge with one N(2)Sr3Bi tetrahedra. In the third N site, N(3) is bonded to one Sr(1), one Sr(2), one Sr(3), and one Bi(1) atom to form NSr3Bi tetrahedra that share corners with three equivalent N(2)Sr3Bi tetrahedra, corners with three equivalent N(1)Sr2Bi3 trigonal bipyramids, corners with three equivalent N(4)Sr3Bi2 trigonal bipyramids, and corners with three equivalent N(5)Sr2Bi2 trigonal pyramids. In the fourth N site, N(4) is bonded to one Sr(1), one Sr(2), one Sr(3), one Bi(2), and one Bi(3) atom to form NSr3Bi2 trigonal bipyramids that share corners with three equivalent N(3)Sr3Bi tetrahedra, corners with four equivalent N(2)Sr3Bi tetrahedra,  a cornercorner with one N(5)Sr2Bi2 trigonal pyramid, edges with two equivalent N(1)Sr2Bi3 trigonal bipyramids, and  an edgeedge with one N(5)Sr2Bi2 trigonal pyramid. In the fifth N site, N(5) is bonded to two equivalent Sr(2), one Bi(1), and one Bi(3) atom to form distorted NSr2Bi2 trigonal pyramids that share corners with three equivalent N(3)Sr3Bi tetrahedra,  a cornercorner with one N(4)Sr3Bi2 trigonal bipyramid, corners with two equivalent N(1)Sr2Bi3 trigonal bipyramids,  an edgeedge with one N(1)Sr2Bi3 trigonal bipyramid,  an edgeedge with one N(4)Sr3Bi2 trigonal bipyramid, and  an edgeedge with one N(5)Sr2Bi2 trigonal pyramid.
Sr3Bi3N5 crystallizes in the triclinic P-1 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 4-coordinate geometry to one N(3), one N(4), and two equivalent N(2) atoms. The Sr(1)-N(3) bond length is 2.66 Å. The Sr(1)-N(4) bond length is 2.92 Å. There is one shorter (2.50 Å) and one longer (2.63 Å) Sr(1)-N(2) bond length. In the second Sr site, Sr(2) is bonded in a 5-coordinate geometry to one N(1), one N(3), one N(4), and two equivalent N(5) atoms. The Sr(2)-N(1) bond length is 2.77 Å. The Sr(2)-N(3) bond length is 2.72 Å. The Sr(2)-N(4) bond length is 2.71 Å. There is one shorter (2.52 Å) and one longer (2.67 Å) Sr(2)-N(5) bond length. In the third Sr site, Sr(3) is bonded in a 4-coordinate geometry to one N(1), one N(2), one N(3), and one N(4) atom. The Sr(3)-N(1) bond length is 2.93 Å. The Sr(3)-N(2) bond length is 2.57 Å. The Sr(3)-N(3) bond length is 2.57 Å. The Sr(3)-N(4) bond length is 2.61 Å. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a distorted trigonal non-coplanar geometry to one N(1), one N(3), and one N(5) atom. The Bi(1)-N(1) bond length is 2.36 Å. The Bi(1)-N(3) bond length is 2.13 Å. The Bi(1)-N(5) bond length is 2.21 Å. In the second Bi site, Bi(2) is bonded in a distorted trigonal non-coplanar geometry to one N(1), one N(2), and one N(4) atom. The Bi(2)-N(1) bond length is 2.24 Å. The Bi(2)-N(2) bond length is 2.13 Å. The Bi(2)-N(4) bond length is 2.31 Å. In the third Bi site, Bi(3) is bonded in a 3-coordinate geometry to one N(1), one N(4), and one N(5) atom. The Bi(3)-N(1) bond length is 2.25 Å. The Bi(3)-N(4) bond length is 2.22 Å. The Bi(3)-N(5) bond length is 2.21 Å. There are five inequivalent N sites. In the first N site, N(1) is bonded to one Sr(2), one Sr(3), one Bi(1), one Bi(2), and one Bi(3) atom to form NSr2Bi3 trigonal bipyramids that share corners with two equivalent N(2)Sr3Bi tetrahedra, corners with three equivalent N(3)Sr3Bi tetrahedra, corners with two equivalent N(5)Sr2Bi2 trigonal pyramids, edges with two equivalent N(4)Sr3Bi2 trigonal bipyramids, and  an edgeedge with one N(5)Sr2Bi2 trigonal pyramid. In the second N site, N(2) is bonded to one Sr(3), two equivalent Sr(1), and one Bi(2) atom to form distorted NSr3Bi tetrahedra that share corners with three equivalent N(3)Sr3Bi tetrahedra, corners with two equivalent N(1)Sr2Bi3 trigonal bipyramids, corners with four equivalent N(4)Sr3Bi2 trigonal bipyramids, and  an edgeedge with one N(2)Sr3Bi tetrahedra. In the third N site, N(3) is bonded to one Sr(1), one Sr(2), one Sr(3), and one Bi(1) atom to form NSr3Bi tetrahedra that share corners with three equivalent N(2)Sr3Bi tetrahedra, corners with three equivalent N(1)Sr2Bi3 trigonal bipyramids, corners with three equivalent N(4)Sr3Bi2 trigonal bipyramids, and corners with three equivalent N(5)Sr2Bi2 trigonal pyramids. In the fourth N site, N(4) is bonded to one Sr(1), one Sr(2), one Sr(3), one Bi(2), and one Bi(3) atom to form NSr3Bi2 trigonal bipyramids that share corners with three equivalent N(3)Sr3Bi tetrahedra, corners with four equivalent N(2)Sr3Bi tetrahedra,  a cornercorner with one N(5)Sr2Bi2 trigonal pyramid, edges with two equivalent N(1)Sr2Bi3 trigonal bipyramids, and  an edgeedge with one N(5)Sr2Bi2 trigonal pyramid. In the fifth N site, N(5) is bonded to two equivalent Sr(2), one Bi(1), and one Bi(3) atom to form distorted NSr2Bi2 trigonal pyramids that share corners with three equivalent N(3)Sr3Bi tetrahedra,  a cornercorner with one N(4)Sr3Bi2 trigonal bipyramid, corners with two equivalent N(1)Sr2Bi3 trigonal bipyramids,  an edgeedge with one N(1)Sr2Bi3 trigonal bipyramid,  an edgeedge with one N(4)Sr3Bi2 trigonal bipyramid, and  an edgeedge with one N(5)Sr2Bi2 trigonal pyramid.