Ca2Ti6N2O11 crystallizes in the monoclinic Cm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one N(1), two equivalent N(2), one O(8), two equivalent O(11), and two equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(10), and two equivalent O(9) atoms. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one N(2), two equivalent N(1), one O(1), one O(3), and one O(6) atom to form distorted TiN3O3 octahedra that share  a cornercorner with one Ti(3)O6 octahedra, corners with two equivalent Ti(1)N3O3 octahedra,  an edgeedge with one Ti(2)O6 octahedra, and edges with two equivalent Ti(4)NO5 octahedra. The corner-sharing octahedral tilt angles range from 20-33°. In the second Ti site, Ti(2) is bonded to one O(1), one O(2), one O(6), one O(7), and two equivalent O(4) atoms to form distorted TiO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra,  an edgeedge with one Ti(1)N3O3 octahedra,  an edgeedge with one Ti(3)O6 octahedra, and edges with two equivalent Ti(4)NO5 octahedra. The corner-sharing octahedral tilt angles are 34°. 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(5) atoms to form distorted TiO6 octahedra that share  a cornercorner with one Ti(1)N3O3 octahedra, corners with two equivalent Ti(3)O6 octahedra, and  an edgeedge with one Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 20-30°. In the fourth Ti site, Ti(4) is bonded to one N(1), one O(10), one O(4), one O(9), and two equivalent O(6) atoms to form distorted TiNO5 octahedra that share corners with two equivalent Ti(4)NO5 octahedra, edges with two equivalent Ti(1)N3O3 octahedra, and edges with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles are 21°. In the fifth Ti site, Ti(5) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(4), one O(5), and two equivalent O(7) atoms. In the sixth Ti site, Ti(6) is bonded in a 6-coordinate geometry to one N(2), one O(11), one O(5), one O(9), and two equivalent O(8) atoms. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ti(4), and two equivalent Ti(1) atoms. In the second N site, N(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca(1), one Ti(1), and one Ti(6) atom. There are eleven inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(2), one Ti(1), and one Ti(2) atom to form distorted OCa2Ti2 tetrahedra that share corners with two equivalent O(1)Ca2Ti2 tetrahedra,  a cornercorner with one O(7)Ti4 trigonal pyramid, corners with two equivalent O(10)Ca2Ti2 trigonal pyramids, corners with two equivalent O(4)Ti4 trigonal pyramids, and  an edgeedge with one O(10)Ca2Ti2 trigonal pyramid. In the second O site, O(2) is bonded in a water-like geometry to 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 Ca(1), one Ti(1), and one Ti(3) atom. In the fourth O site, O(4) 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(1)Ca2Ti2 tetrahedra,  a cornercorner with one O(5)Ti4 trigonal pyramid, corners with two equivalent O(4)Ti4 trigonal pyramids,  an edgeedge with one O(10)Ca2Ti2 trigonal pyramid, and edges with two equivalent O(7)Ti4 trigonal pyramids. In the fifth O site, O(5) is bonded to one Ti(5), one Ti(6), and two equivalent Ti(3) atoms to form distorted OTi4 trigonal pyramids that share  a cornercorner with one O(10)Ca2Ti2 trigonal pyramid,  a cornercorner with one O(4)Ti4 trigonal pyramid, corners with two equivalent O(5)Ti4 trigonal pyramids, and edges with two equivalent O(7)Ti4 trigonal pyramids. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ca(2), one Ti(1), one Ti(2), and two equivalent Ti(4) atoms. 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 O(1)Ca2Ti2 tetrahedra, corners with two equivalent O(10)Ca2Ti2 trigonal pyramids, corners with two equivalent O(7)Ti4 trigonal pyramids, edges with two equivalent O(4)Ti4 trigonal pyramids, and edges with two equivalent O(5)Ti4 trigonal pyramids. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ca(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 Ca(2), one Ti(4), and one Ti(6) atom. In the tenth O site, O(10) is bonded to two equivalent Ca(2), one Ti(4), and one Ti(5) atom to form distorted OCa2Ti2 trigonal pyramids that share corners with two equivalent O(1)Ca2Ti2 tetrahedra,  a cornercorner with one O(5)Ti4 trigonal pyramid, corners with two equivalent O(10)Ca2Ti2 trigonal pyramids, corners with two equivalent O(7)Ti4 trigonal pyramids,  an edgeedge with one O(1)Ca2Ti2 tetrahedra, and  an edgeedge with one O(4)Ti4 trigonal pyramid. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Ti(5), and one Ti(6) atom.
Ca2Ti6N2O11 crystallizes in the monoclinic Cm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one N(1), two equivalent N(2), one O(8), two equivalent O(11), and two equivalent O(3) atoms. The Ca(1)-N(1) bond length is 3.00 Å. Both Ca(1)-N(2) bond lengths are 2.61 Å. The Ca(1)-O(8) bond length is 2.87 Å. Both Ca(1)-O(11) bond lengths are 2.46 Å. Both Ca(1)-O(3) bond lengths are 2.64 Å. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(10), and two equivalent O(9) atoms. The Ca(2)-O(6) bond length is 2.91 Å. Both Ca(2)-O(1) bond lengths are 2.58 Å. Both Ca(2)-O(10) bond lengths are 2.50 Å. Both Ca(2)-O(9) bond lengths are 2.62 Å. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one N(2), two equivalent N(1), one O(1), one O(3), and one O(6) atom to form distorted TiN3O3 octahedra that share  a cornercorner with one Ti(3)O6 octahedra, corners with two equivalent Ti(1)N3O3 octahedra,  an edgeedge with one Ti(2)O6 octahedra, and edges with two equivalent Ti(4)NO5 octahedra. The corner-sharing octahedral tilt angles range from 20-33°. The Ti(1)-N(2) bond length is 1.82 Å. Both Ti(1)-N(1) bond lengths are 1.96 Å. The Ti(1)-O(1) bond length is 2.11 Å. The Ti(1)-O(3) bond length is 2.12 Å. The Ti(1)-O(6) bond length is 2.43 Å. In the second Ti site, Ti(2) is bonded to one O(1), one O(2), one O(6), one O(7), and two equivalent O(4) atoms to form distorted TiO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra,  an edgeedge with one Ti(1)N3O3 octahedra,  an edgeedge with one Ti(3)O6 octahedra, and edges with two equivalent Ti(4)NO5 octahedra. The corner-sharing octahedral tilt angles are 34°. The Ti(2)-O(1) bond length is 1.87 Å. The Ti(2)-O(2) bond length is 1.80 Å. The Ti(2)-O(6) bond length is 2.25 Å. The Ti(2)-O(7) bond length is 2.21 Å. Both Ti(2)-O(4) bond lengths are 1.96 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(5) atoms to form distorted TiO6 octahedra that share  a cornercorner with one Ti(1)N3O3 octahedra, corners with two equivalent Ti(3)O6 octahedra, and  an edgeedge with one Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 20-30°. The Ti(3)-O(2) bond length is 1.95 Å. The Ti(3)-O(3) bond length is 1.78 Å. The Ti(3)-O(7) bond length is 2.25 Å. The Ti(3)-O(8) bond length is 2.09 Å. Both Ti(3)-O(5) bond lengths are 1.94 Å. In the fourth Ti site, Ti(4) is bonded to one N(1), one O(10), one O(4), one O(9), and two equivalent O(6) atoms to form distorted TiNO5 octahedra that share corners with two equivalent Ti(4)NO5 octahedra, edges with two equivalent Ti(1)N3O3 octahedra, and edges with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles are 21°. The Ti(4)-N(1) bond length is 1.86 Å. The Ti(4)-O(10) bond length is 2.34 Å. The Ti(4)-O(4) bond length is 2.14 Å. The Ti(4)-O(9) bond length is 1.89 Å. Both Ti(4)-O(6) bond lengths are 1.91 Å. In the fifth Ti site, Ti(5) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(4), one O(5), and two equivalent O(7) atoms. The Ti(5)-O(10) bond length is 1.82 Å. The Ti(5)-O(11) bond length is 1.80 Å. The Ti(5)-O(4) bond length is 2.32 Å. The Ti(5)-O(5) bond length is 2.35 Å. Both Ti(5)-O(7) bond lengths are 1.99 Å. In the sixth Ti site, Ti(6) is bonded in a 6-coordinate geometry to one N(2), one O(11), one O(5), one O(9), and two equivalent O(8) atoms. The Ti(6)-N(2) bond length is 1.82 Å. The Ti(6)-O(11) bond length is 2.41 Å. The Ti(6)-O(5) bond length is 2.22 Å. The Ti(6)-O(9) bond length is 1.90 Å. Both Ti(6)-O(8) bond lengths are 1.94 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ti(4), and two equivalent Ti(1) atoms. In the second N site, N(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca(1), one Ti(1), and one Ti(6) atom. There are eleven inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(2), one Ti(1), and one Ti(2) atom to form distorted OCa2Ti2 tetrahedra that share corners with two equivalent O(1)Ca2Ti2 tetrahedra,  a cornercorner with one O(7)Ti4 trigonal pyramid, corners with two equivalent O(10)Ca2Ti2 trigonal pyramids, corners with two equivalent O(4)Ti4 trigonal pyramids, and  an edgeedge with one O(10)Ca2Ti2 trigonal pyramid. In the second O site, O(2) is bonded in a water-like geometry to 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 Ca(1), one Ti(1), and one Ti(3) atom. In the fourth O site, O(4) 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(1)Ca2Ti2 tetrahedra,  a cornercorner with one O(5)Ti4 trigonal pyramid, corners with two equivalent O(4)Ti4 trigonal pyramids,  an edgeedge with one O(10)Ca2Ti2 trigonal pyramid, and edges with two equivalent O(7)Ti4 trigonal pyramids. In the fifth O site, O(5) is bonded to one Ti(5), one Ti(6), and two equivalent Ti(3) atoms to form distorted OTi4 trigonal pyramids that share  a cornercorner with one O(10)Ca2Ti2 trigonal pyramid,  a cornercorner with one O(4)Ti4 trigonal pyramid, corners with two equivalent O(5)Ti4 trigonal pyramids, and edges with two equivalent O(7)Ti4 trigonal pyramids. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ca(2), one Ti(1), one Ti(2), and two equivalent Ti(4) atoms. 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 O(1)Ca2Ti2 tetrahedra, corners with two equivalent O(10)Ca2Ti2 trigonal pyramids, corners with two equivalent O(7)Ti4 trigonal pyramids, edges with two equivalent O(4)Ti4 trigonal pyramids, and edges with two equivalent O(5)Ti4 trigonal pyramids. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ca(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 Ca(2), one Ti(4), and one Ti(6) atom. In the tenth O site, O(10) is bonded to two equivalent Ca(2), one Ti(4), and one Ti(5) atom to form distorted OCa2Ti2 trigonal pyramids that share corners with two equivalent O(1)Ca2Ti2 tetrahedra,  a cornercorner with one O(5)Ti4 trigonal pyramid, corners with two equivalent O(10)Ca2Ti2 trigonal pyramids, corners with two equivalent O(7)Ti4 trigonal pyramids,  an edgeedge with one O(1)Ca2Ti2 tetrahedra, and  an edgeedge with one O(4)Ti4 trigonal pyramid. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Ti(5), and one Ti(6) atom.