Sr2MgTi6N2O11 crystallizes in the monoclinic Cm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(6), two equivalent O(10), two equivalent O(2), and two equivalent O(3) atoms. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to two equivalent N(2), two equivalent O(1), and two equivalent O(9) atoms. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(4), one O(8), and two equivalent O(11) atoms. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one N(1), one O(11), one O(3), and two equivalent O(4) atoms to form TiNO4 trigonal bipyramids that share  a cornercorner with one Ti(3)O6 octahedra,  a cornercorner with one Ti(6)NO4 trigonal bipyramid, corners with two equivalent Ti(1)NO4 trigonal bipyramids, and edges with two equivalent Ti(4)N3O3 octahedra. The corner-sharing octahedral tilt angles are 22°. In the second Ti site, Ti(2) is bonded in a 6-coordinate geometry to one N(1), one O(1), one O(2), one O(7), and two equivalent O(5) atoms. In the third Ti site, Ti(3) is bonded to one O(2), one O(3), one O(7), one O(8), and two equivalent O(6) atoms to form TiO6 octahedra that share corners with two equivalent Ti(3)O6 octahedra,  a cornercorner with one Ti(1)NO4 trigonal bipyramid, and edges with two equivalent Ti(6)NO4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 19°. In the fourth Ti site, Ti(4) is bonded to one N(2), two equivalent N(1), one O(4), one O(5), and one O(9) atom to form TiN3O3 octahedra that share corners with two equivalent Ti(4)N3O3 octahedra,  a cornercorner with one Ti(6)NO4 trigonal bipyramid, and edges with two equivalent Ti(1)NO4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 24°. In the fifth Ti site, Ti(5) is bonded in a 6-coordinate geometry to one O(10), one O(5), one O(6), one O(9), and two equivalent O(7) atoms. In the sixth Ti site, Ti(6) is bonded to one N(2), one O(11), one O(6), and two equivalent O(8) atoms to form distorted TiNO4 trigonal bipyramids that share  a cornercorner with one Ti(4)N3O3 octahedra,  a cornercorner with one Ti(1)NO4 trigonal bipyramid, corners with two equivalent Ti(6)NO4 trigonal bipyramids, and edges with two equivalent Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles are 26°. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted see-saw-like geometry to one Ti(1), one Ti(2), and two equivalent Ti(4) atoms. In the second N site, N(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Sr(2), one Ti(4), and one Ti(6) atom. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Sr(2) and one Ti(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Ti(2), and one Ti(3) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr(1), one Ti(1), and one Ti(3) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Ti(4), and two equivalent Ti(1) atoms. In the fifth O site, O(5) is bonded to one Ti(4), one Ti(5), and two equivalent Ti(2) atoms to form distorted OTi4 trigonal pyramids that share corners with two equivalent O(5)Ti4 trigonal pyramids and  an edgeedge with one O(9)Sr2Ti2 trigonal pyramid. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(1), one Ti(5), one Ti(6), and two equivalent Ti(3) atoms. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ti(2), one Ti(3), and two equivalent Ti(5) atoms. In the eighth O site, O(8) is bonded in a square co-planar geometry to one Mg(1), one Ti(3), and two equivalent Ti(6) atoms. In the ninth O site, O(9) is bonded to two equivalent Sr(2), one Ti(4), and one Ti(5) atom to form distorted OSr2Ti2 trigonal pyramids that share corners with two equivalent O(9)Sr2Ti2 trigonal pyramids and  an edgeedge with one O(5)Ti4 trigonal pyramid. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to two equivalent Sr(1) and one Ti(5) atom. In the eleventh O site, O(11) is bonded in a square co-planar geometry to two equivalent Mg(1), one Ti(1), and one Ti(6) atom.
Sr2MgTi6N2O11 crystallizes in the monoclinic Cm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(6), two equivalent O(10), two equivalent O(2), and two equivalent O(3) atoms. The Sr(1)-O(6) bond length is 3.00 Å. Both Sr(1)-O(10) bond lengths are 2.60 Å. Both Sr(1)-O(2) bond lengths are 2.54 Å. Both Sr(1)-O(3) bond lengths are 2.78 Å. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to two equivalent N(2), two equivalent O(1), and two equivalent O(9) atoms. Both Sr(2)-N(2) bond lengths are 2.79 Å. Both Sr(2)-O(1) bond lengths are 2.63 Å. Both Sr(2)-O(9) bond lengths are 2.51 Å. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(4), one O(8), and two equivalent O(11) atoms. The Mg(1)-O(4) bond length is 1.93 Å. The Mg(1)-O(8) bond length is 1.94 Å. Both Mg(1)-O(11) bond lengths are 1.96 Å. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one N(1), one O(11), one O(3), and two equivalent O(4) atoms to form TiNO4 trigonal bipyramids that share  a cornercorner with one Ti(3)O6 octahedra,  a cornercorner with one Ti(6)NO4 trigonal bipyramid, corners with two equivalent Ti(1)NO4 trigonal bipyramids, and edges with two equivalent Ti(4)N3O3 octahedra. The corner-sharing octahedral tilt angles are 22°. The Ti(1)-N(1) bond length is 1.98 Å. The Ti(1)-O(11) bond length is 2.09 Å. The Ti(1)-O(3) bond length is 1.85 Å. Both Ti(1)-O(4) bond lengths are 1.98 Å. In the second Ti site, Ti(2) is bonded in a 6-coordinate geometry to one N(1), one O(1), one O(2), one O(7), and two equivalent O(5) atoms. The Ti(2)-N(1) bond length is 2.08 Å. The Ti(2)-O(1) bond length is 1.76 Å. The Ti(2)-O(2) bond length is 2.04 Å. The Ti(2)-O(7) bond length is 2.55 Å. Both Ti(2)-O(5) bond lengths are 2.01 Å. In the third Ti site, Ti(3) is bonded to one O(2), one O(3), one O(7), one O(8), and two equivalent O(6) atoms to form TiO6 octahedra that share corners with two equivalent Ti(3)O6 octahedra,  a cornercorner with one Ti(1)NO4 trigonal bipyramid, and edges with two equivalent Ti(6)NO4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 19°. The Ti(3)-O(2) bond length is 1.89 Å. The Ti(3)-O(3) bond length is 2.03 Å. The Ti(3)-O(7) bond length is 2.07 Å. The Ti(3)-O(8) bond length is 2.10 Å. Both Ti(3)-O(6) bond lengths are 1.98 Å. In the fourth Ti site, Ti(4) is bonded to one N(2), two equivalent N(1), one O(4), one O(5), and one O(9) atom to form TiN3O3 octahedra that share corners with two equivalent Ti(4)N3O3 octahedra,  a cornercorner with one Ti(6)NO4 trigonal bipyramid, and edges with two equivalent Ti(1)NO4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 24°. The Ti(4)-N(2) bond length is 1.97 Å. Both Ti(4)-N(1) bond lengths are 2.00 Å. The Ti(4)-O(4) bond length is 2.12 Å. The Ti(4)-O(5) bond length is 2.22 Å. The Ti(4)-O(9) bond length is 2.04 Å. In the fifth Ti site, Ti(5) is bonded in a 6-coordinate geometry to one O(10), one O(5), one O(6), one O(9), and two equivalent O(7) atoms. The Ti(5)-O(10) bond length is 1.77 Å. The Ti(5)-O(5) bond length is 2.44 Å. The Ti(5)-O(6) bond length is 2.23 Å. The Ti(5)-O(9) bond length is 1.86 Å. Both Ti(5)-O(7) bond lengths are 2.01 Å. In the sixth Ti site, Ti(6) is bonded to one N(2), one O(11), one O(6), and two equivalent O(8) atoms to form distorted TiNO4 trigonal bipyramids that share  a cornercorner with one Ti(4)N3O3 octahedra,  a cornercorner with one Ti(1)NO4 trigonal bipyramid, corners with two equivalent Ti(6)NO4 trigonal bipyramids, and edges with two equivalent Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles are 26°. The Ti(6)-N(2) bond length is 1.79 Å. The Ti(6)-O(11) bond length is 2.10 Å. The Ti(6)-O(6) bond length is 2.09 Å. Both Ti(6)-O(8) bond lengths are 2.02 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted see-saw-like geometry to one Ti(1), one Ti(2), and two equivalent Ti(4) atoms. In the second N site, N(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Sr(2), one Ti(4), and one Ti(6) atom. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Sr(2) and one Ti(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Ti(2), and one Ti(3) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr(1), one Ti(1), and one Ti(3) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Ti(4), and two equivalent Ti(1) atoms. In the fifth O site, O(5) is bonded to one Ti(4), one Ti(5), and two equivalent Ti(2) atoms to form distorted OTi4 trigonal pyramids that share corners with two equivalent O(5)Ti4 trigonal pyramids and  an edgeedge with one O(9)Sr2Ti2 trigonal pyramid. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(1), one Ti(5), one Ti(6), and two equivalent Ti(3) atoms. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ti(2), one Ti(3), and two equivalent Ti(5) atoms. In the eighth O site, O(8) is bonded in a square co-planar geometry to one Mg(1), one Ti(3), and two equivalent Ti(6) atoms. In the ninth O site, O(9) is bonded to two equivalent Sr(2), one Ti(4), and one Ti(5) atom to form distorted OSr2Ti2 trigonal pyramids that share corners with two equivalent O(9)Sr2Ti2 trigonal pyramids and  an edgeedge with one O(5)Ti4 trigonal pyramid. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to two equivalent Sr(1) and one Ti(5) atom. In the eleventh O site, O(11) is bonded in a square co-planar geometry to two equivalent Mg(1), one Ti(1), and one Ti(6) atom.