Sr2CaTi6N2O11 crystallizes in the triclinic P1 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(10), one O(5), two equivalent O(1), two equivalent O(2), and two equivalent O(9) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent N(2), one O(4), one O(8), two equivalent O(1), and two equivalent O(11) atoms. Ca(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. 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(2)NO5 octahedra,  a cornercorner with one Ti(3)O6 octahedra,  a cornercorner with one Ti(6)NO4 square pyramid, and corners with two equivalent Ti(1)NO4 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 21-63°. 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 distorted TiNO5 octahedra that share corners with two equivalent Ti(2)NO5 octahedra,  a cornercorner with one Ti(1)NO4 trigonal bipyramid,  an edgeedge with one Ti(3)O6 octahedra, and edges with two equivalent Ti(5)O6 octahedra. The corner-sharing octahedral tilt angles are 18°. 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,  an edgeedge with one Ti(2)NO5 octahedra, edges with two equivalent Ti(5)O6 octahedra, and edges with two equivalent Ti(6)NO4 square pyramids. The corner-sharing octahedral tilt angles are 27°. In the fourth Ti site, Ti(4) is bonded in a 6-coordinate geometry to one N(2), two equivalent N(1), one O(4), one O(5), and one O(9) atom. In the fifth Ti site, Ti(5) is bonded to one O(10), one O(5), one O(6), one O(9), and two equivalent O(7) atoms to form distorted TiO6 octahedra that share corners with two equivalent Ti(5)O6 octahedra,  a cornercorner with one Ti(6)NO4 square pyramid, edges with two equivalent Ti(2)NO5 octahedra, and edges with two equivalent Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles are 26°. 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 square pyramids that share  a cornercorner with one Ti(5)O6 octahedra, corners with two equivalent Ti(6)NO4 square pyramids,  a cornercorner with one Ti(1)NO4 trigonal bipyramid, and edges with two equivalent Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles are 71°. 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 tetrahedra that share  a cornercorner with one O(11)Sr2Ca2Ti2 octahedra, corners with two equivalent N(1)Ti4 tetrahedra,  a cornercorner with one O(2)Sr2Ti2 trigonal pyramid, and  a cornercorner with one O(7)Ti4 trigonal pyramid. The corner-sharing octahedral tilt angles are 46°. 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 in a 5-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and one Ti(2) atom. In the second O site, O(2) is bonded to two equivalent Sr(1), one Ti(2), and one Ti(3) atom to form distorted OSr2Ti2 trigonal pyramids that share  a cornercorner with one N(1)Ti4 tetrahedra, corners with two equivalent O(6)Ti4 tetrahedra, corners with two equivalent O(2)Sr2Ti2 trigonal pyramids, and  an edgeedge with one O(7)Ti4 trigonal pyramid. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Ca(1), one Ti(1), and one Ti(3) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Sr(2), one Ca(1), one Ti(4), and two equivalent Ti(1) atoms. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Sr(1), 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 tetrahedra that share  a cornercorner with one O(11)Sr2Ca2Ti2 octahedra, corners with two equivalent O(6)Ti4 tetrahedra, corners with two equivalent O(2)Sr2Ti2 trigonal pyramids, and edges with two equivalent O(7)Ti4 trigonal pyramids. The corner-sharing octahedral tilt angles are 42°. In the seventh O site, O(7) is bonded to one Ti(2), one Ti(3), and two equivalent Ti(5) atoms to form distorted OTi4 trigonal pyramids that share  a cornercorner with one N(1)Ti4 tetrahedra, corners with two equivalent O(7)Ti4 trigonal pyramids, edges with two equivalent O(6)Ti4 tetrahedra, and  an edgeedge with one O(2)Sr2Ti2 trigonal pyramid. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Sr(2), one Ca(1), one Ti(3), and two equivalent Ti(6) atoms. In the ninth O site, O(9) is bonded in a 3-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 4-coordinate geometry to one Sr(1), two equivalent Ca(1), and one Ti(5) atom. In the eleventh O site, O(11) is bonded to two equivalent Sr(2), two equivalent Ca(1), one Ti(1), and one Ti(6) atom to form distorted OSr2Ca2Ti2 octahedra that share  a cornercorner with one N(1)Ti4 tetrahedra,  a cornercorner with one O(6)Ti4 tetrahedra, and edges with two equivalent O(11)Sr2Ca2Ti2 octahedra.
Sr2CaTi6N2O11 crystallizes in the triclinic P1 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(10), one O(5), two equivalent O(1), two equivalent O(2), and two equivalent O(9) atoms. The Sr(1)-O(10) bond length is 2.69 Å. The Sr(1)-O(5) bond length is 2.78 Å. There is one shorter (2.67 Å) and one longer (2.93 Å) Sr(1)-O(1) bond length. There is one shorter (2.46 Å) and one longer (2.56 Å) Sr(1)-O(2) bond length. There is one shorter (2.55 Å) and one longer (3.19 Å) Sr(1)-O(9) bond length. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent N(2), one O(4), one O(8), two equivalent O(1), and two equivalent O(11) atoms. There is one shorter (2.67 Å) and one longer (2.75 Å) Sr(2)-N(2) bond length. The Sr(2)-O(4) bond length is 2.62 Å. The Sr(2)-O(8) bond length is 2.81 Å. There is one shorter (2.54 Å) and one longer (2.62 Å) Sr(2)-O(1) bond length. There is one shorter (2.67 Å) and one longer (2.72 Å) Sr(2)-O(11) bond length. Ca(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 Ca(1)-O(4) bond length is 2.59 Å. The Ca(1)-O(8) bond length is 2.39 Å. There is one shorter (2.48 Å) and one longer (2.58 Å) Ca(1)-O(10) bond length. There is one shorter (2.46 Å) and one longer (2.60 Å) Ca(1)-O(11) bond length. There is one shorter (2.60 Å) and one longer (2.94 Å) Ca(1)-O(3) bond length. 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(2)NO5 octahedra,  a cornercorner with one Ti(3)O6 octahedra,  a cornercorner with one Ti(6)NO4 square pyramid, and corners with two equivalent Ti(1)NO4 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 21-63°. The Ti(1)-N(1) bond length is 1.99 Å. The Ti(1)-O(11) bond length is 2.01 Å. The Ti(1)-O(3) bond length is 1.86 Å. There is one shorter (1.96 Å) and one longer (1.99 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 distorted TiNO5 octahedra that share corners with two equivalent Ti(2)NO5 octahedra,  a cornercorner with one Ti(1)NO4 trigonal bipyramid,  an edgeedge with one Ti(3)O6 octahedra, and edges with two equivalent Ti(5)O6 octahedra. The corner-sharing octahedral tilt angles are 18°. The Ti(2)-N(1) bond length is 1.95 Å. The Ti(2)-O(1) bond length is 1.83 Å. The Ti(2)-O(2) bond length is 2.34 Å. The Ti(2)-O(7) bond length is 2.18 Å. There is one shorter (1.95 Å) and one longer (1.98 Å) Ti(2)-O(5) bond length. 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,  an edgeedge with one Ti(2)NO5 octahedra, edges with two equivalent Ti(5)O6 octahedra, and edges with two equivalent Ti(6)NO4 square pyramids. The corner-sharing octahedral tilt angles are 27°. The Ti(3)-O(2) bond length is 1.82 Å. The Ti(3)-O(3) bond length is 1.97 Å. The Ti(3)-O(7) bond length is 2.21 Å. The Ti(3)-O(8) bond length is 2.22 Å. Both Ti(3)-O(6) bond lengths are 2.00 Å. In the fourth Ti site, Ti(4) is bonded in a 6-coordinate geometry to one N(2), two equivalent N(1), one O(4), one O(5), and one O(9) atom. The Ti(4)-N(2) bond length is 1.90 Å. There is one shorter (2.01 Å) and one longer (2.04 Å) Ti(4)-N(1) bond length. The Ti(4)-O(4) bond length is 2.22 Å. The Ti(4)-O(5) bond length is 2.49 Å. The Ti(4)-O(9) bond length is 1.99 Å. In the fifth Ti site, Ti(5) is bonded to one O(10), one O(5), one O(6), one O(9), and two equivalent O(7) atoms to form distorted TiO6 octahedra that share corners with two equivalent Ti(5)O6 octahedra,  a cornercorner with one Ti(6)NO4 square pyramid, edges with two equivalent Ti(2)NO5 octahedra, and edges with two equivalent Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles are 26°. The Ti(5)-O(10) bond length is 1.82 Å. The Ti(5)-O(5) bond length is 2.25 Å. The Ti(5)-O(6) bond length is 2.21 Å. The Ti(5)-O(9) bond length is 1.93 Å. There is one shorter (1.99 Å) and one longer (2.00 Å) Ti(5)-O(7) bond length. 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 square pyramids that share  a cornercorner with one Ti(5)O6 octahedra, corners with two equivalent Ti(6)NO4 square pyramids,  a cornercorner with one Ti(1)NO4 trigonal bipyramid, and edges with two equivalent Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles are 71°. The Ti(6)-N(2) bond length is 1.83 Å. The Ti(6)-O(11) bond length is 1.97 Å. The Ti(6)-O(6) bond length is 2.05 Å. There is one shorter (1.99 Å) and one longer (2.00 Å) Ti(6)-O(8) bond length. 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 tetrahedra that share  a cornercorner with one O(11)Sr2Ca2Ti2 octahedra, corners with two equivalent N(1)Ti4 tetrahedra,  a cornercorner with one O(2)Sr2Ti2 trigonal pyramid, and  a cornercorner with one O(7)Ti4 trigonal pyramid. The corner-sharing octahedral tilt angles are 46°. 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 in a 5-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and one Ti(2) atom. In the second O site, O(2) is bonded to two equivalent Sr(1), one Ti(2), and one Ti(3) atom to form distorted OSr2Ti2 trigonal pyramids that share  a cornercorner with one N(1)Ti4 tetrahedra, corners with two equivalent O(6)Ti4 tetrahedra, corners with two equivalent O(2)Sr2Ti2 trigonal pyramids, and  an edgeedge with one O(7)Ti4 trigonal pyramid. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Ca(1), one Ti(1), and one Ti(3) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Sr(2), one Ca(1), one Ti(4), and two equivalent Ti(1) atoms. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Sr(1), 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 tetrahedra that share  a cornercorner with one O(11)Sr2Ca2Ti2 octahedra, corners with two equivalent O(6)Ti4 tetrahedra, corners with two equivalent O(2)Sr2Ti2 trigonal pyramids, and edges with two equivalent O(7)Ti4 trigonal pyramids. The corner-sharing octahedral tilt angles are 42°. In the seventh O site, O(7) is bonded to one Ti(2), one Ti(3), and two equivalent Ti(5) atoms to form distorted OTi4 trigonal pyramids that share  a cornercorner with one N(1)Ti4 tetrahedra, corners with two equivalent O(7)Ti4 trigonal pyramids, edges with two equivalent O(6)Ti4 tetrahedra, and  an edgeedge with one O(2)Sr2Ti2 trigonal pyramid. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Sr(2), one Ca(1), one Ti(3), and two equivalent Ti(6) atoms. In the ninth O site, O(9) is bonded in a 3-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 4-coordinate geometry to one Sr(1), two equivalent Ca(1), and one Ti(5) atom. In the eleventh O site, O(11) is bonded to two equivalent Sr(2), two equivalent Ca(1), one Ti(1), and one Ti(6) atom to form distorted OSr2Ca2Ti2 octahedra that share  a cornercorner with one N(1)Ti4 tetrahedra,  a cornercorner with one O(6)Ti4 tetrahedra, and edges with two equivalent O(11)Sr2Ca2Ti2 octahedra.