Sr2MgTi6N2O11 crystallizes in the triclinic P1 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 5-coordinate geometry to one O(10), two equivalent O(2), and two equivalent O(9) atoms. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one N(1), two equivalent N(2), one O(4), one O(8), two equivalent O(1), and two equivalent O(11) atoms. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(10), one O(11), one O(3), and one O(4) atom. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one N(1), one O(1), one O(11), one O(3), and two equivalent O(4) atoms. In the second Ti site, Ti(2) is bonded to one N(1), one O(1), one O(2), one O(7), and two equivalent O(5) atoms to form TiNO5 octahedra that share corners with two equivalent Ti(2)NO5 octahedra and edges with two equivalent Ti(4)N3O3 octahedra. The corner-sharing octahedral tilt angles are 14°. In the third Ti site, Ti(3) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(7), one O(8), and two equivalent O(6) atoms. 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 distorted 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(2)NO5 octahedra. The corner-sharing octahedral tilt angles are 27°. 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 and corners with two equivalent Ti(6)NO4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 20°. There are two inequivalent N sites. In the first N site, N(1) is bonded in a rectangular see-saw-like geometry to one Sr(2), one Ti(1), one Ti(2), and two equivalent Ti(4) atoms. 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 corner-sharing OSr2Ti2 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Sr(1), one Ti(2), and one Ti(3) atom to form OSr2Ti2 tetrahedra that share corners with two equivalent O(2)Sr2Ti2 tetrahedra,  a cornercorner with one O(1)Sr2Ti2 trigonal pyramid, and corners with two equivalent O(6)Ti4 trigonal pyramids. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Mg(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(2), one Mg(1), one Ti(4), and two equivalent Ti(1) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ti(4), one Ti(5), and two equivalent Ti(2) atoms. In the sixth O site, O(6) is bonded to one Ti(5), one Ti(6), and two equivalent Ti(3) atoms to form distorted OTi4 trigonal pyramids that share corners with two equivalent O(2)Sr2Ti2 tetrahedra and corners with two equivalent O(6)Ti4 trigonal pyramids. In the seventh O site, O(7) is bonded in a 3-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 distorted T-shaped geometry to one Sr(2), one Ti(3), and two equivalent Ti(6) atoms. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Ti(4), and one Ti(5) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Sr(1), one Mg(1), and one Ti(5) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to two equivalent Sr(2), one Mg(1), one Ti(1), and one Ti(6) atom.
Sr2MgTi6N2O11 crystallizes in the triclinic P1 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 5-coordinate geometry to one O(10), two equivalent O(2), and two equivalent O(9) atoms. The Sr(1)-O(10) bond length is 2.56 Å. There is one shorter (2.44 Å) and one longer (2.49 Å) Sr(1)-O(2) bond length. There is one shorter (2.65 Å) and one longer (2.88 Å) Sr(1)-O(9) bond length. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one N(1), two equivalent N(2), one O(4), one O(8), two equivalent O(1), and two equivalent O(11) atoms. The Sr(2)-N(1) bond length is 3.24 Å. There is one shorter (2.56 Å) and one longer (2.59 Å) Sr(2)-N(2) bond length. The Sr(2)-O(4) bond length is 2.97 Å. The Sr(2)-O(8) bond length is 2.82 Å. There is one shorter (2.57 Å) and one longer (2.75 Å) Sr(2)-O(1) bond length. Both Sr(2)-O(11) bond lengths are 2.78 Å. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(10), one O(11), one O(3), and one O(4) atom. The Mg(1)-O(10) bond length is 2.03 Å. The Mg(1)-O(11) bond length is 1.99 Å. The Mg(1)-O(3) bond length is 2.00 Å. The Mg(1)-O(4) bond length is 2.27 Å. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one N(1), one O(1), one O(11), one O(3), and two equivalent O(4) atoms. The Ti(1)-N(1) bond length is 2.06 Å. The Ti(1)-O(1) bond length is 1.95 Å. The Ti(1)-O(11) bond length is 2.08 Å. The Ti(1)-O(3) bond length is 2.60 Å. There is one shorter (1.97 Å) and one longer (1.98 Å) Ti(1)-O(4) bond length. In the second Ti site, Ti(2) is bonded to one N(1), one O(1), one O(2), one O(7), and two equivalent O(5) atoms to form TiNO5 octahedra that share corners with two equivalent Ti(2)NO5 octahedra and edges with two equivalent Ti(4)N3O3 octahedra. The corner-sharing octahedral tilt angles are 14°. The Ti(2)-N(1) bond length is 1.96 Å. The Ti(2)-O(1) bond length is 1.97 Å. The Ti(2)-O(2) bond length is 2.09 Å. The Ti(2)-O(7) bond length is 2.11 Å. Both Ti(2)-O(5) bond lengths are 1.96 Å. In the third Ti site, Ti(3) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(7), one O(8), and two equivalent O(6) atoms. The Ti(3)-O(2) bond length is 1.91 Å. The Ti(3)-O(3) bond length is 1.80 Å. The Ti(3)-O(7) bond length is 2.52 Å. The Ti(3)-O(8) bond length is 2.10 Å. There is one shorter (2.00 Å) and one longer (2.03 Å) Ti(3)-O(6) bond length. 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 distorted 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(2)NO5 octahedra. The corner-sharing octahedral tilt angles are 27°. The Ti(4)-N(2) bond length is 1.85 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 2.46 Å. The Ti(4)-O(9) bond length is 2.35 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 1.84 Å. The Ti(5)-O(5) bond length is 2.20 Å. The Ti(5)-O(6) bond length is 2.45 Å. The Ti(5)-O(9) bond length is 1.83 Å. Both Ti(5)-O(7) bond lengths are 2.00 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 and corners with two equivalent Ti(6)NO4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 20°. The Ti(6)-N(2) bond length is 1.83 Å. The Ti(6)-O(11) bond length is 1.91 Å. The Ti(6)-O(6) bond length is 2.05 Å. There is one shorter (1.95 Å) and one longer (1.99 Å) Ti(6)-O(8) bond length. There are two inequivalent N sites. In the first N site, N(1) is bonded in a rectangular see-saw-like geometry to one Sr(2), one Ti(1), one Ti(2), and two equivalent Ti(4) atoms. 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 corner-sharing OSr2Ti2 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Sr(1), one Ti(2), and one Ti(3) atom to form OSr2Ti2 tetrahedra that share corners with two equivalent O(2)Sr2Ti2 tetrahedra,  a cornercorner with one O(1)Sr2Ti2 trigonal pyramid, and corners with two equivalent O(6)Ti4 trigonal pyramids. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Mg(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(2), one Mg(1), one Ti(4), and two equivalent Ti(1) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ti(4), one Ti(5), and two equivalent Ti(2) atoms. In the sixth O site, O(6) is bonded to one Ti(5), one Ti(6), and two equivalent Ti(3) atoms to form distorted OTi4 trigonal pyramids that share corners with two equivalent O(2)Sr2Ti2 tetrahedra and corners with two equivalent O(6)Ti4 trigonal pyramids. In the seventh O site, O(7) is bonded in a 3-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 distorted T-shaped geometry to one Sr(2), one Ti(3), and two equivalent Ti(6) atoms. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Ti(4), and one Ti(5) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Sr(1), one Mg(1), and one Ti(5) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to two equivalent Sr(2), one Mg(1), one Ti(1), and one Ti(6) atom.