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 8-coordinate geometry to one O(4), one O(8), two equivalent O(10), two equivalent O(11), 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 distorted see-saw-like geometry to one O(5), one O(6), and two equivalent O(2) atoms. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one N(1), one O(1), one O(11), one O(3), and two equivalent O(4) atoms to form TiNO5 octahedra that share corners with two equivalent Ti(1)NO5 octahedra,  a cornercorner with one Ti(6)NO4 trigonal bipyramid,  a cornercorner with one Ti(3)O5 trigonal bipyramid,  an edgeedge with one Ti(2)NO4 trigonal bipyramid, and edges with two equivalent Ti(4)N3O2 trigonal bipyramids. The corner-sharing octahedral tilt angles are 20°. In the second Ti site, Ti(2) is bonded to one N(1), one O(1), one O(7), and two equivalent O(5) atoms to form distorted TiNO4 trigonal bipyramids that share corners with two equivalent Ti(4)N3O2 trigonal bipyramids, corners with two equivalent Ti(2)NO4 trigonal bipyramids, and  an edgeedge with one Ti(1)NO5 octahedra. In the third Ti site, Ti(3) is bonded to one O(2), one O(3), one O(8), and two equivalent O(6) atoms to form distorted TiO5 trigonal bipyramids that share  a cornercorner with one Ti(1)NO5 octahedra, corners with two equivalent Ti(3)O5 trigonal bipyramids, and edges with two equivalent Ti(6)NO4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 30°. In the fourth Ti site, Ti(4) is bonded to one N(2), two equivalent N(1), one O(4), and one O(9) atom to form distorted TiN3O2 trigonal bipyramids that share  a cornercorner with one Ti(6)NO4 trigonal bipyramid, corners with two equivalent Ti(4)N3O2 trigonal bipyramids, corners with two equivalent Ti(2)NO4 trigonal bipyramids, and edges with two equivalent Ti(1)NO5 octahedra. In the fifth Ti site, Ti(5) is bonded in a 5-coordinate geometry to one O(10), one O(5), 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(1)NO5 octahedra,  a cornercorner with one Ti(4)N3O2 trigonal bipyramid, corners with two equivalent Ti(6)NO4 trigonal bipyramids, and edges with two equivalent Ti(3)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 25°. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Ti(1), one Ti(2), and two equivalent Ti(4) atoms to form NTi4 trigonal pyramids that share corners with two equivalent N(1)Ti4 trigonal pyramids, corners with two equivalent O(5)MgTi3 trigonal pyramids, and  an edgeedge with one O(1)Sr2Ti2 tetrahedra. In the second N site, N(2) is bonded in a distorted rectangular see-saw-like 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 to two equivalent Sr(2), one Ti(1), and one Ti(2) atom to form distorted OSr2Ti2 tetrahedra that share corners with two equivalent O(1)Sr2Ti2 tetrahedra, corners with two equivalent O(5)MgTi3 trigonal pyramids, and  an edgeedge with one N(1)Ti4 trigonal pyramid. In the second O site, O(2) is bonded in a distorted T-shaped geometry to two equivalent Mg(1) 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 4-coordinate geometry to one Sr(1), one Ti(4), and two equivalent Ti(1) atoms. In the fifth O site, O(5) is bonded to one Mg(1), one Ti(5), and two equivalent Ti(2) atoms to form distorted OMgTi3 trigonal pyramids that share corners with two equivalent O(1)Sr2Ti2 tetrahedra, corners with two equivalent N(1)Ti4 trigonal pyramids, and corners with two equivalent O(5)MgTi3 trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted square co-planar geometry to one Mg(1), one Ti(6), and two equivalent Ti(3) atoms. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Ti(2) and two equivalent Ti(5) atoms. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(1), one Ti(3), and two equivalent Ti(6) atoms. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr(2), one Ti(4), and one Ti(5) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to two equivalent Sr(1) and one Ti(5) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr(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 8-coordinate geometry to one O(4), one O(8), two equivalent O(10), two equivalent O(11), and two equivalent O(3) atoms. The Sr(1)-O(4) bond length is 2.72 Å. The Sr(1)-O(8) bond length is 2.78 Å. Both Sr(1)-O(10) bond lengths are 2.54 Å. Both Sr(1)-O(11) bond lengths are 2.61 Å. Both Sr(1)-O(3) bond lengths are 2.67 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 2.73 Å. Both Sr(2)-O(1) bond lengths are 2.64 Å. Both Sr(2)-O(9) bond lengths are 2.66 Å. Mg(1) is bonded in a distorted see-saw-like geometry to one O(5), one O(6), and two equivalent O(2) atoms. The Mg(1)-O(5) bond length is 1.99 Å. The Mg(1)-O(6) bond length is 2.01 Å. Both Mg(1)-O(2) 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(1), one O(11), one O(3), and two equivalent O(4) atoms to form TiNO5 octahedra that share corners with two equivalent Ti(1)NO5 octahedra,  a cornercorner with one Ti(6)NO4 trigonal bipyramid,  a cornercorner with one Ti(3)O5 trigonal bipyramid,  an edgeedge with one Ti(2)NO4 trigonal bipyramid, and edges with two equivalent Ti(4)N3O2 trigonal bipyramids. The corner-sharing octahedral tilt angles are 20°. The Ti(1)-N(1) bond length is 2.06 Å. The Ti(1)-O(1) bond length is 2.01 Å. The Ti(1)-O(11) bond length is 2.03 Å. The Ti(1)-O(3) bond length is 2.29 Å. Both Ti(1)-O(4) bond lengths are 1.95 Å. In the second Ti site, Ti(2) is bonded to one N(1), one O(1), one O(7), and two equivalent O(5) atoms to form distorted TiNO4 trigonal bipyramids that share corners with two equivalent Ti(4)N3O2 trigonal bipyramids, corners with two equivalent Ti(2)NO4 trigonal bipyramids, and  an edgeedge with one Ti(1)NO5 octahedra. The Ti(2)-N(1) bond length is 1.88 Å. The Ti(2)-O(1) bond length is 1.96 Å. The Ti(2)-O(7) bond length is 2.04 Å. Both Ti(2)-O(5) bond lengths are 1.99 Å. In the third Ti site, Ti(3) is bonded to one O(2), one O(3), one O(8), and two equivalent O(6) atoms to form distorted TiO5 trigonal bipyramids that share  a cornercorner with one Ti(1)NO5 octahedra, corners with two equivalent Ti(3)O5 trigonal bipyramids, and edges with two equivalent Ti(6)NO4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 30°. The Ti(3)-O(2) bond length is 1.98 Å. The Ti(3)-O(3) bond length is 1.77 Å. The Ti(3)-O(8) bond length is 2.01 Å. Both Ti(3)-O(6) bond lengths are 1.97 Å. In the fourth Ti site, Ti(4) is bonded to one N(2), two equivalent N(1), one O(4), and one O(9) atom to form distorted TiN3O2 trigonal bipyramids that share  a cornercorner with one Ti(6)NO4 trigonal bipyramid, corners with two equivalent Ti(4)N3O2 trigonal bipyramids, corners with two equivalent Ti(2)NO4 trigonal bipyramids, and edges with two equivalent Ti(1)NO5 octahedra. The Ti(4)-N(2) bond length is 1.83 Å. Both Ti(4)-N(1) bond lengths are 2.03 Å. The Ti(4)-O(4) bond length is 2.07 Å. The Ti(4)-O(9) bond length is 2.26 Å. In the fifth Ti site, Ti(5) is bonded in a 5-coordinate geometry to one O(10), one O(5), one O(9), and two equivalent O(7) atoms. The Ti(5)-O(10) bond length is 1.75 Å. The Ti(5)-O(5) bond length is 2.31 Å. The Ti(5)-O(9) bond length is 1.82 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(1)NO5 octahedra,  a cornercorner with one Ti(4)N3O2 trigonal bipyramid, corners with two equivalent Ti(6)NO4 trigonal bipyramids, and edges with two equivalent Ti(3)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 25°. The Ti(6)-N(2) bond length is 1.83 Å. The Ti(6)-O(11) bond length is 1.84 Å. The Ti(6)-O(6) bond length is 2.12 Å. Both Ti(6)-O(8) bond lengths are 1.99 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Ti(1), one Ti(2), and two equivalent Ti(4) atoms to form NTi4 trigonal pyramids that share corners with two equivalent N(1)Ti4 trigonal pyramids, corners with two equivalent O(5)MgTi3 trigonal pyramids, and  an edgeedge with one O(1)Sr2Ti2 tetrahedra. In the second N site, N(2) is bonded in a distorted rectangular see-saw-like 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 to two equivalent Sr(2), one Ti(1), and one Ti(2) atom to form distorted OSr2Ti2 tetrahedra that share corners with two equivalent O(1)Sr2Ti2 tetrahedra, corners with two equivalent O(5)MgTi3 trigonal pyramids, and  an edgeedge with one N(1)Ti4 trigonal pyramid. In the second O site, O(2) is bonded in a distorted T-shaped geometry to two equivalent Mg(1) 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 4-coordinate geometry to one Sr(1), one Ti(4), and two equivalent Ti(1) atoms. In the fifth O site, O(5) is bonded to one Mg(1), one Ti(5), and two equivalent Ti(2) atoms to form distorted OMgTi3 trigonal pyramids that share corners with two equivalent O(1)Sr2Ti2 tetrahedra, corners with two equivalent N(1)Ti4 trigonal pyramids, and corners with two equivalent O(5)MgTi3 trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted square co-planar geometry to one Mg(1), one Ti(6), and two equivalent Ti(3) atoms. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Ti(2) and two equivalent Ti(5) atoms. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(1), one Ti(3), and two equivalent Ti(6) atoms. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr(2), one Ti(4), and one Ti(5) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to two equivalent Sr(1) and one Ti(5) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr(1), one Ti(1), and one Ti(6) atom.