La6Ti3O5Se9 crystallizes in the monoclinic Cm space group. There are twelve inequivalent La sites. In the first La site, La(1) is bonded in a 8-coordinate geometry to one Se(15), two equivalent Se(16), two equivalent Se(18), two equivalent Se(6), and one O(10) atom. In the second La site, La(2) is bonded in a 8-coordinate geometry to one Se(13), two equivalent Se(5), two equivalent Se(6), one O(9), and two equivalent O(2) atoms. In the third La site, La(3) is bonded in a 8-coordinate geometry to one Se(17), two equivalent Se(11), two equivalent Se(14), one O(3), and two equivalent O(7) atoms. In the fourth La site, La(4) is bonded to one Se(12), one Se(5), one Se(6), two equivalent Se(15), and two equivalent Se(2) atoms to form distorted edge-sharing LaSe7 pentagonal bipyramids. In the fifth La site, La(5) is bonded in a 3-coordinate geometry to one Se(16), one Se(5), two equivalent Se(13), two equivalent Se(2), one O(7), and two equivalent O(3) atoms. In the sixth La site, La(6) is bonded in a 5-coordinate geometry to one Se(12), one Se(18), two equivalent Se(3), one O(8), two equivalent O(1), and two equivalent O(10) atoms. In the seventh La site, La(7) is bonded in a 8-coordinate geometry to one Se(10), two equivalent Se(14), two equivalent Se(7), two equivalent Se(8), and one O(6) atom. In the eighth La site, La(8) is bonded in a 3-coordinate geometry to one Se(11), one Se(8), two equivalent Se(1), two equivalent Se(17), one O(2), and two equivalent O(9) atoms. In the ninth La site, La(9) is bonded in a 5-coordinate geometry to one Se(4), one Se(7), two equivalent Se(9), one O(1), two equivalent O(6), and two equivalent O(8) atoms. In the tenth La site, La(10) is bonded in a 3-coordinate geometry to one Se(12), one Se(18), two equivalent Se(15), two equivalent Se(3), one O(5), and two equivalent O(4) atoms. In the eleventh La site, La(11) is bonded in a 3-coordinate geometry to one Se(4), one Se(7), two equivalent Se(10), two equivalent Se(9), one O(4), and two equivalent O(5) atoms. In the twelfth La site, La(12) is bonded in a 7-coordinate geometry to one Se(11), one Se(14), one Se(4), two equivalent Se(1), and two equivalent Se(10) atoms. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent Se(18), two equivalent Se(9), one O(1), and one O(4) atom to form distorted edge-sharing TiSe4O2 octahedra. In the second Ti site, Ti(2) is bonded in a distorted single-bond geometry to one Se(1), two equivalent Se(4), two equivalent Se(8), and one O(6) atom. In the third Ti site, Ti(3) is bonded in a distorted single-bond geometry to one Se(2), two equivalent Se(12), two equivalent Se(16), and one O(10) atom. In the fourth Ti site, Ti(4) is bonded in a distorted linear geometry to two equivalent Se(13), two equivalent Se(17), one O(2), and one O(7) atom. In the fifth Ti site, Ti(5) is bonded to two equivalent Se(3), two equivalent Se(7), one O(5), and one O(8) atom to form distorted edge-sharing TiSe4O2 octahedra. In the sixth Ti site, Ti(6) is bonded in a distorted linear geometry to two equivalent Se(11), two equivalent Se(5), one O(3), and one O(9) atom. There are eighteen inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent La(12), two equivalent La(8), and one Ti(2) atom to form distorted SeLa4Ti trigonal bipyramids that share corners with two equivalent Se(14)La5 square pyramids,  a cornercorner with one O(6)La3Ti tetrahedra, corners with two equivalent O(2)La3Ti tetrahedra, corners with two equivalent O(9)La3Ti tetrahedra, corners with two equivalent Se(10)La5 trigonal bipyramids, edges with two equivalent Se(11)La4Ti2 pentagonal pyramids,  an edgeedge with one O(9)La3Ti tetrahedra,  an edgeedge with one Se(10)La5 trigonal bipyramid, edges with two equivalent Se(4)La3Ti2 trigonal bipyramids, and edges with two equivalent Se(1)La4Ti trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent La(4), two equivalent La(5), and one Ti(3) atom to form distorted SeLa4Ti trigonal bipyramids that share corners with two equivalent Se(6)La5 square pyramids,  a cornercorner with one O(10)La3Ti tetrahedra, corners with two equivalent O(3)La3Ti tetrahedra, corners with two equivalent O(7)La3Ti tetrahedra, corners with two equivalent Se(15)La5 trigonal bipyramids, edges with two equivalent Se(5)La4Ti2 pentagonal pyramids,  an edgeedge with one O(3)La3Ti tetrahedra,  an edgeedge with one Se(15)La5 trigonal bipyramid, edges with two equivalent Se(12)La3Ti2 trigonal bipyramids, and edges with two equivalent Se(2)La4Ti trigonal bipyramids. In the third Se site, Se(3) is bonded in a 6-coordinate geometry to two equivalent La(10), two equivalent La(6), and two equivalent Ti(5) atoms. In the fourth Se site, Se(4) is bonded to one La(11), one La(12), one La(9), and two equivalent Ti(2) atoms to form distorted SeLa3Ti2 trigonal bipyramids that share corners with two equivalent Se(7)La4Ti2 octahedra,  a cornercorner with one Se(11)La4Ti2 pentagonal pyramid,  a cornercorner with one Se(14)La5 square pyramid,  a cornercorner with one O(1)La3Ti tetrahedra,  a cornercorner with one O(4)La3Ti tetrahedra, corners with two equivalent O(5)La3Ti tetrahedra, corners with two equivalent O(8)La3Ti tetrahedra, corners with two equivalent Se(4)La3Ti2 trigonal bipyramids, edges with two equivalent O(6)La3Ti tetrahedra, edges with two equivalent Se(1)La4Ti trigonal bipyramids, and edges with two equivalent Se(10)La5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 58-61°. In the fifth Se site, Se(5) is bonded to one La(4), one La(5), two equivalent La(2), and two equivalent Ti(6) atoms to form distorted SeLa4Ti2 pentagonal pyramids that share corners with two equivalent Se(11)La4Ti2 pentagonal pyramids, corners with two equivalent Se(6)La5 square pyramids,  a cornercorner with one O(7)La3Ti tetrahedra, corners with two equivalent O(2)La3Ti tetrahedra,  a cornercorner with one Se(12)La3Ti2 trigonal bipyramid, corners with two equivalent Se(15)La5 trigonal bipyramids,  an edgeedge with one Se(11)La4Ti2 pentagonal pyramid, edges with two equivalent Se(5)La4Ti2 pentagonal pyramids,  an edgeedge with one O(2)La3Ti tetrahedra, edges with two equivalent O(3)La3Ti tetrahedra, edges with two equivalent O(9)La3Ti tetrahedra, edges with two equivalent Se(2)La4Ti trigonal bipyramids, and  a faceface with one Se(6)La5 square pyramid. In the sixth Se site, Se(6) is bonded to one La(4), two equivalent La(1), and two equivalent La(2) atoms to form distorted SeLa5 square pyramids that share corners with two equivalent Se(18)La4Ti2 octahedra, corners with two equivalent Se(5)La4Ti2 pentagonal pyramids, corners with two equivalent O(10)La3Ti tetrahedra, corners with two equivalent O(2)La3Ti tetrahedra, corners with two equivalent O(9)La3Ti tetrahedra,  a cornercorner with one Se(12)La3Ti2 trigonal bipyramid, corners with two equivalent Se(2)La4Ti trigonal bipyramids,  an edgeedge with one Se(18)La4Ti2 octahedra, edges with two equivalent Se(6)La5 square pyramids,  an edgeedge with one O(2)La3Ti tetrahedra, edges with two equivalent Se(15)La5 trigonal bipyramids, and  a faceface with one Se(5)La4Ti2 pentagonal pyramid. The corner-sharing octahedral tilt angles are 34°. In the seventh Se site, Se(7) is bonded to one La(11), one La(9), two equivalent La(7), and two equivalent Ti(5) atoms to form distorted SeLa4Ti2 octahedra that share corners with two equivalent Se(14)La5 square pyramids,  a cornercorner with one O(1)La3Ti tetrahedra,  a cornercorner with one O(4)La3Ti tetrahedra, corners with two equivalent Se(4)La3Ti2 trigonal bipyramids, edges with two equivalent Se(7)La4Ti2 octahedra,  an edgeedge with one Se(14)La5 square pyramid, edges with two equivalent O(5)La3Ti tetrahedra, edges with two equivalent O(6)La3Ti tetrahedra, edges with two equivalent O(8)La3Ti tetrahedra, and edges with two equivalent Se(10)La5 trigonal bipyramids. In the eighth Se site, Se(8) is bonded in a 5-coordinate geometry to one La(8), two equivalent La(7), and two equivalent Ti(2) atoms. In the ninth Se site, Se(9) is bonded in a 6-coordinate geometry to two equivalent La(11), two equivalent La(9), and two equivalent Ti(1) atoms. In the tenth Se site, Se(10) is bonded to one La(7), two equivalent La(11), and two equivalent La(12) atoms to form distorted SeLa5 trigonal bipyramids that share corners with two equivalent Se(11)La4Ti2 pentagonal pyramids,  a cornercorner with one O(6)La3Ti tetrahedra, corners with two equivalent O(4)La3Ti tetrahedra, corners with two equivalent O(5)La3Ti tetrahedra, corners with two equivalent Se(1)La4Ti trigonal bipyramids, edges with two equivalent Se(7)La4Ti2 octahedra, edges with two equivalent Se(14)La5 square pyramids,  an edgeedge with one O(5)La3Ti tetrahedra,  an edgeedge with one Se(1)La4Ti trigonal bipyramid, edges with two equivalent Se(4)La3Ti2 trigonal bipyramids, and edges with two equivalent Se(10)La5 trigonal bipyramids. In the eleventh Se site, Se(11) is bonded to one La(12), one La(8), two equivalent La(3), and two equivalent Ti(6) atoms to form distorted SeLa4Ti2 pentagonal pyramids that share corners with two equivalent Se(5)La4Ti2 pentagonal pyramids, corners with two equivalent Se(14)La5 square pyramids,  a cornercorner with one O(2)La3Ti tetrahedra, corners with two equivalent O(7)La3Ti tetrahedra,  a cornercorner with one Se(4)La3Ti2 trigonal bipyramid, corners with two equivalent Se(10)La5 trigonal bipyramids,  an edgeedge with one Se(5)La4Ti2 pentagonal pyramid, edges with two equivalent Se(11)La4Ti2 pentagonal pyramids,  an edgeedge with one O(7)La3Ti tetrahedra, edges with two equivalent O(3)La3Ti tetrahedra, edges with two equivalent O(9)La3Ti tetrahedra, edges with two equivalent Se(1)La4Ti trigonal bipyramids, and  a faceface with one Se(14)La5 square pyramid. In the twelfth Se site, Se(12) is bonded to one La(10), one La(4), one La(6), and two equivalent Ti(3) atoms to form distorted SeLa3Ti2 trigonal bipyramids that share corners with two equivalent Se(18)La4Ti2 octahedra,  a cornercorner with one Se(5)La4Ti2 pentagonal pyramid,  a cornercorner with one Se(6)La5 square pyramid,  a cornercorner with one O(5)La3Ti tetrahedra,  a cornercorner with one O(8)La3Ti tetrahedra, corners with two equivalent O(1)La3Ti tetrahedra, corners with two equivalent O(4)La3Ti tetrahedra, corners with two equivalent Se(12)La3Ti2 trigonal bipyramids, edges with two equivalent O(10)La3Ti tetrahedra, edges with two equivalent Se(2)La4Ti trigonal bipyramids, and edges with two equivalent Se(15)La5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 58-61°. In the thirteenth Se site, Se(13) is bonded in a distorted pentagonal planar geometry to one La(2), two equivalent La(5), and two equivalent Ti(4) atoms. In the fourteenth Se site, Se(14) is bonded to one La(12), two equivalent La(3), and two equivalent La(7) atoms to form SeLa5 square pyramids that share corners with two equivalent Se(7)La4Ti2 octahedra, corners with two equivalent Se(11)La4Ti2 pentagonal pyramids, corners with two equivalent O(3)La3Ti tetrahedra, corners with two equivalent O(6)La3Ti tetrahedra, corners with two equivalent O(7)La3Ti tetrahedra,  a cornercorner with one Se(4)La3Ti2 trigonal bipyramid, corners with two equivalent Se(1)La4Ti trigonal bipyramids,  an edgeedge with one Se(7)La4Ti2 octahedra, edges with two equivalent Se(14)La5 square pyramids,  an edgeedge with one O(7)La3Ti tetrahedra, edges with two equivalent Se(10)La5 trigonal bipyramids, and  a faceface with one Se(11)La4Ti2 pentagonal pyramid. The corner-sharing octahedral tilt angles are 33°. In the fifteenth Se site, Se(15) is bonded to one La(1), two equivalent La(10), and two equivalent La(4) atoms to form distorted SeLa5 trigonal bipyramids that share corners with two equivalent Se(5)La4Ti2 pentagonal pyramids,  a cornercorner with one O(10)La3Ti tetrahedra, corners with two equivalent O(4)La3Ti tetrahedra, corners with two equivalent O(5)La3Ti tetrahedra, corners with two equivalent Se(2)La4Ti trigonal bipyramids, edges with two equivalent Se(18)La4Ti2 octahedra, edges with two equivalent Se(6)La5 square pyramids,  an edgeedge with one O(4)La3Ti tetrahedra,  an edgeedge with one Se(2)La4Ti trigonal bipyramid, edges with two equivalent Se(12)La3Ti2 trigonal bipyramids, and edges with two equivalent Se(15)La5 trigonal bipyramids. In the sixteenth Se site, Se(16) is bonded in a 5-coordinate geometry to one La(5), two equivalent La(1), and two equivalent Ti(3) atoms. In the seventeenth Se site, Se(17) is bonded in a distorted pentagonal planar geometry to one La(3), two equivalent La(8), and two equivalent Ti(4) atoms. In the eighteenth Se site, Se(18) is bonded to one La(10), one La(6), two equivalent La(1), and two equivalent Ti(1) atoms to form distorted SeLa4Ti2 octahedra that share corners with two equivalent Se(6)La5 square pyramids,  a cornercorner with one O(5)La3Ti tetrahedra,  a cornercorner with one O(8)La3Ti tetrahedra, corners with two equivalent Se(12)La3Ti2 trigonal bipyramids, edges with two equivalent Se(18)La4Ti2 octahedra,  an edgeedge with one Se(6)La5 square pyramid, edges with two equivalent O(1)La3Ti tetrahedra, edges with two equivalent O(10)La3Ti tetrahedra, edges with two equivalent O(4)La3Ti tetrahedra, and edges with two equivalent Se(15)La5 trigonal bipyramids. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one La(9), two equivalent La(6), and one Ti(1) atom to form OLa3Ti tetrahedra that share  a cornercorner with one Se(7)La4Ti2 octahedra,  a cornercorner with one O(4)La3Ti tetrahedra, corners with two equivalent O(1)La3Ti tetrahedra, corners with two equivalent O(10)La3Ti tetrahedra, corners with two equivalent O(6)La3Ti tetrahedra,  a cornercorner with one Se(4)La3Ti2 trigonal bipyramid, corners with two equivalent Se(12)La3Ti2 trigonal bipyramids, edges with two equivalent Se(18)La4Ti2 octahedra,  an edgeedge with one O(10)La3Ti tetrahedra, and edges with two equivalent O(8)La3Ti tetrahedra. The corner-sharing octahedral tilt angles are 56°. In the second O site, O(2) is bonded to one La(8), two equivalent La(2), and one Ti(4) atom to form OLa3Ti tetrahedra that share  a cornercorner with one Se(11)La4Ti2 pentagonal pyramid, corners with two equivalent Se(5)La4Ti2 pentagonal pyramids, corners with two equivalent Se(6)La5 square pyramids,  a cornercorner with one O(7)La3Ti tetrahedra, corners with two equivalent O(2)La3Ti tetrahedra, corners with two equivalent Se(1)La4Ti trigonal bipyramids,  an edgeedge with one Se(5)La4Ti2 pentagonal pyramid,  an edgeedge with one Se(6)La5 square pyramid, and edges with two equivalent O(9)La3Ti tetrahedra. In the third O site, O(3) is bonded to one La(3), two equivalent La(5), and one Ti(6) atom to form OLa3Ti tetrahedra that share corners with two equivalent Se(14)La5 square pyramids,  a cornercorner with one O(9)La3Ti tetrahedra, corners with two equivalent O(3)La3Ti tetrahedra, corners with two equivalent Se(2)La4Ti trigonal bipyramids, edges with two equivalent Se(11)La4Ti2 pentagonal pyramids, edges with two equivalent Se(5)La4Ti2 pentagonal pyramids, edges with two equivalent O(7)La3Ti tetrahedra, and  an edgeedge with one Se(2)La4Ti trigonal bipyramid. In the fourth O site, O(4) is bonded to one La(11), two equivalent La(10), and one Ti(1) atom to form OLa3Ti tetrahedra that share  a cornercorner with one Se(7)La4Ti2 octahedra,  a cornercorner with one O(1)La3Ti tetrahedra, corners with two equivalent O(4)La3Ti tetrahedra,  a cornercorner with one Se(4)La3Ti2 trigonal bipyramid, corners with two equivalent Se(12)La3Ti2 trigonal bipyramids, corners with two equivalent Se(10)La5 trigonal bipyramids, corners with two equivalent Se(15)La5 trigonal bipyramids, edges with two equivalent Se(18)La4Ti2 octahedra, edges with two equivalent O(5)La3Ti tetrahedra, and  an edgeedge with one Se(15)La5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 59°. In the fifth O site, O(5) is bonded to one La(10), two equivalent La(11), and one Ti(5) atom to form OLa3Ti tetrahedra that share  a cornercorner with one Se(18)La4Ti2 octahedra,  a cornercorner with one O(8)La3Ti tetrahedra, corners with two equivalent O(5)La3Ti tetrahedra,  a cornercorner with one Se(12)La3Ti2 trigonal bipyramid, corners with two equivalent Se(4)La3Ti2 trigonal bipyramids, corners with two equivalent Se(10)La5 trigonal bipyramids, corners with two equivalent Se(15)La5 trigonal bipyramids, edges with two equivalent Se(7)La4Ti2 octahedra, edges with two equivalent O(4)La3Ti tetrahedra, and  an edgeedge with one Se(10)La5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 59°. In the sixth O site, O(6) is bonded to one La(7), two equivalent La(9), and one Ti(2) atom to form distorted OLa3Ti tetrahedra that share corners with two equivalent Se(14)La5 square pyramids, corners with two equivalent O(1)La3Ti tetrahedra, corners with two equivalent O(6)La3Ti tetrahedra, corners with two equivalent O(8)La3Ti tetrahedra,  a cornercorner with one Se(1)La4Ti trigonal bipyramid,  a cornercorner with one Se(10)La5 trigonal bipyramid, edges with two equivalent Se(7)La4Ti2 octahedra,  an edgeedge with one O(8)La3Ti tetrahedra, and edges with two equivalent Se(4)La3Ti2 trigonal bipyramids. In the seventh O site, O(7) is bonded to one La(5), two equivalent La(3), and one Ti(4) atom to form OLa3Ti tetrahedra that share  a cornercorner with one Se(5)La4Ti2 pentagonal pyramid, corners with two equivalent Se(11)La4Ti2 pentagonal pyramids, corners with two equivalent Se(14)La5 square pyramids,  a cornercorner with one O(2)La3Ti tetrahedra, corners with two equivalent O(7)La3Ti tetrahedra, corners with two equivalent Se(2)La4Ti trigonal bipyramids,  an edgeedge with one Se(11)La4Ti2 pentagonal pyramid,  an edgeedge with one Se(14)La5 square pyramid, and edges with two equivalent O(3)La3Ti tetrahedra. In the eighth O site, O(8) is bonded to one La(6), two equivalent La(9), and one Ti(5) atom to form OLa3Ti tetrahedra that share  a cornercorner with one Se(18)La4Ti2 octahedra,  a cornercorner with one O(5)La3Ti tetrahedra, corners with two equivalent O(10)La3Ti tetrahedra, corners with two equivalent O(6)La3Ti tetrahedra, corners with two equivalent O(8)La3Ti tetrahedra,  a cornercorner with one Se(12)La3Ti2 trigonal bipyramid, corners with two equivalent Se(4)La3Ti2 trigonal bipyramids, edges with two equivalent Se(7)La4Ti2 octahedra,  an edgeedge with one O(6)La3Ti tetrahedra, and edges with two equivalent O(1)La3Ti tetrahedra. The corner-sharing octahedral tilt angles are 56°. In the ninth O site, O(9) is bonded to one La(2), two equivalent La(8), and one Ti(6) atom to form OLa3Ti tetrahedra that share corners with two equivalent Se(6)La5 square pyramids,  a cornercorner with one O(3)La3Ti tetrahedra, corners with two equivalent O(9)La3Ti tetrahedra, corners with two equivalent Se(1)La4Ti trigonal bipyramids, edges with two equivalent Se(11)La4Ti2 pentagonal pyramids, edges with two equivalent Se(5)La4Ti2 pentagonal pyramids, edges with two equivalent O(2)La3Ti tetrahedra, and  an edgeedge with one Se(1)La4Ti trigonal bipyramid. In the tenth O site, O(10) is bonded to one La(1), two equivalent La(6), and one Ti(3) atom to form distorted OLa3Ti tetrahedra that share corners with two equivalent Se(6)La5 square pyramids, corners with two equivalent O(1)La3Ti tetrahedra, corners with two equivalent O(10)La3Ti tetrahedra, corners with two equivalent O(8)La3Ti tetrahedra,  a cornercorner with one Se(2)La4Ti trigonal bipyramid,  a cornercorner with one Se(15)La5 trigonal bipyramid, edges with two equivalent Se(18)La4Ti2 octahedra,  an edgeedge with one O(1)La3Ti tetrahedra, and edges with two equivalent Se(12)La3Ti2 trigonal bipyramids.
La6Ti3O5Se9 crystallizes in the monoclinic Cm space group. There are twelve inequivalent La sites. In the first La site, La(1) is bonded in a 8-coordinate geometry to one Se(15), two equivalent Se(16), two equivalent Se(18), two equivalent Se(6), and one O(10) atom. The La(1)-Se(15) bond length is 3.21 Å. Both La(1)-Se(16) bond lengths are 3.12 Å. Both La(1)-Se(18) bond lengths are 3.01 Å. Both La(1)-Se(6) bond lengths are 3.09 Å. The La(1)-O(10) bond length is 2.70 Å. In the second La site, La(2) is bonded in a 8-coordinate geometry to one Se(13), two equivalent Se(5), two equivalent Se(6), one O(9), and two equivalent O(2) atoms. The La(2)-Se(13) bond length is 3.06 Å. Both La(2)-Se(5) bond lengths are 3.20 Å. Both La(2)-Se(6) bond lengths are 3.17 Å. The La(2)-O(9) bond length is 2.53 Å. Both La(2)-O(2) bond lengths are 2.37 Å. In the third La site, La(3) is bonded in a 8-coordinate geometry to one Se(17), two equivalent Se(11), two equivalent Se(14), one O(3), and two equivalent O(7) atoms. The La(3)-Se(17) bond length is 3.07 Å. Both La(3)-Se(11) bond lengths are 3.20 Å. Both La(3)-Se(14) bond lengths are 3.18 Å. The La(3)-O(3) bond length is 2.54 Å. Both La(3)-O(7) bond lengths are 2.38 Å. In the fourth La site, La(4) is bonded to one Se(12), one Se(5), one Se(6), two equivalent Se(15), and two equivalent Se(2) atoms to form distorted edge-sharing LaSe7 pentagonal bipyramids. The La(4)-Se(12) bond length is 3.05 Å. The La(4)-Se(5) bond length is 3.18 Å. The La(4)-Se(6) bond length is 3.01 Å. Both La(4)-Se(15) bond lengths are 2.93 Å. Both La(4)-Se(2) bond lengths are 3.02 Å. In the fifth La site, La(5) is bonded in a 3-coordinate geometry to one Se(16), one Se(5), two equivalent Se(13), two equivalent Se(2), one O(7), and two equivalent O(3) atoms. The La(5)-Se(16) bond length is 3.66 Å. The La(5)-Se(5) bond length is 3.18 Å. Both La(5)-Se(13) bond lengths are 3.18 Å. Both La(5)-Se(2) bond lengths are 3.09 Å. The La(5)-O(7) bond length is 2.57 Å. Both La(5)-O(3) bond lengths are 2.43 Å. In the sixth La site, La(6) is bonded in a 5-coordinate geometry to one Se(12), one Se(18), two equivalent Se(3), one O(8), two equivalent O(1), and two equivalent O(10) atoms. The La(6)-Se(12) bond length is 3.26 Å. The La(6)-Se(18) bond length is 3.17 Å. Both La(6)-Se(3) bond lengths are 3.38 Å. The La(6)-O(8) bond length is 2.44 Å. Both La(6)-O(1) bond lengths are 2.47 Å. Both La(6)-O(10) bond lengths are 2.65 Å. In the seventh La site, La(7) is bonded in a 8-coordinate geometry to one Se(10), two equivalent Se(14), two equivalent Se(7), two equivalent Se(8), and one O(6) atom. The La(7)-Se(10) bond length is 3.21 Å. Both La(7)-Se(14) bond lengths are 3.15 Å. Both La(7)-Se(7) bond lengths are 3.01 Å. Both La(7)-Se(8) bond lengths are 3.17 Å. The La(7)-O(6) bond length is 2.65 Å. In the eighth La site, La(8) is bonded in a 3-coordinate geometry to one Se(11), one Se(8), two equivalent Se(1), two equivalent Se(17), one O(2), and two equivalent O(9) atoms. The La(8)-Se(11) bond length is 3.17 Å. The La(8)-Se(8) bond length is 3.68 Å. Both La(8)-Se(1) bond lengths are 3.16 Å. Both La(8)-Se(17) bond lengths are 3.18 Å. The La(8)-O(2) bond length is 2.57 Å. Both La(8)-O(9) bond lengths are 2.43 Å. In the ninth La site, La(9) is bonded in a 5-coordinate geometry to one Se(4), one Se(7), two equivalent Se(9), one O(1), two equivalent O(6), and two equivalent O(8) atoms. The La(9)-Se(4) bond length is 3.26 Å. The La(9)-Se(7) bond length is 3.17 Å. Both La(9)-Se(9) bond lengths are 3.38 Å. The La(9)-O(1) bond length is 2.44 Å. Both La(9)-O(6) bond lengths are 2.72 Å. Both La(9)-O(8) bond lengths are 2.47 Å. In the tenth La site, La(10) is bonded in a 3-coordinate geometry to one Se(12), one Se(18), two equivalent Se(15), two equivalent Se(3), one O(5), and two equivalent O(4) atoms. The La(10)-Se(12) bond length is 3.51 Å. The La(10)-Se(18) bond length is 3.30 Å. Both La(10)-Se(15) bond lengths are 3.25 Å. Both La(10)-Se(3) bond lengths are 3.25 Å. The La(10)-O(5) bond length is 2.50 Å. Both La(10)-O(4) bond lengths are 2.43 Å. In the eleventh La site, La(11) is bonded in a 3-coordinate geometry to one Se(4), one Se(7), two equivalent Se(10), two equivalent Se(9), one O(4), and two equivalent O(5) atoms. The La(11)-Se(4) bond length is 3.51 Å. The La(11)-Se(7) bond length is 3.30 Å. Both La(11)-Se(10) bond lengths are 3.25 Å. Both La(11)-Se(9) bond lengths are 3.25 Å. The La(11)-O(4) bond length is 2.50 Å. Both La(11)-O(5) bond lengths are 2.43 Å. In the twelfth La site, La(12) is bonded in a 7-coordinate geometry to one Se(11), one Se(14), one Se(4), two equivalent Se(1), and two equivalent Se(10) atoms. The La(12)-Se(11) bond length is 3.29 Å. The La(12)-Se(14) bond length is 3.06 Å. The La(12)-Se(4) bond length is 3.05 Å. Both La(12)-Se(1) bond lengths are 3.02 Å. Both La(12)-Se(10) bond lengths are 2.93 Å. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent Se(18), two equivalent Se(9), one O(1), and one O(4) atom to form distorted edge-sharing TiSe4O2 octahedra. Both Ti(1)-Se(18) bond lengths are 2.73 Å. Both Ti(1)-Se(9) bond lengths are 2.65 Å. The Ti(1)-O(1) bond length is 1.96 Å. The Ti(1)-O(4) bond length is 1.99 Å. In the second Ti site, Ti(2) is bonded in a distorted single-bond geometry to one Se(1), two equivalent Se(4), two equivalent Se(8), and one O(6) atom. The Ti(2)-Se(1) bond length is 2.72 Å. Both Ti(2)-Se(4) bond lengths are 2.63 Å. Both Ti(2)-Se(8) bond lengths are 2.71 Å. The Ti(2)-O(6) bond length is 1.82 Å. In the third Ti site, Ti(3) is bonded in a distorted single-bond geometry to one Se(2), two equivalent Se(12), two equivalent Se(16), and one O(10) atom. The Ti(3)-Se(2) bond length is 2.81 Å. Both Ti(3)-Se(12) bond lengths are 2.60 Å. Both Ti(3)-Se(16) bond lengths are 2.70 Å. The Ti(3)-O(10) bond length is 1.80 Å. In the fourth Ti site, Ti(4) is bonded in a distorted linear geometry to two equivalent Se(13), two equivalent Se(17), one O(2), and one O(7) atom. Both Ti(4)-Se(13) bond lengths are 2.73 Å. Both Ti(4)-Se(17) bond lengths are 2.72 Å. The Ti(4)-O(2) bond length is 1.94 Å. The Ti(4)-O(7) bond length is 1.93 Å. In the fifth Ti site, Ti(5) is bonded to two equivalent Se(3), two equivalent Se(7), one O(5), and one O(8) atom to form distorted edge-sharing TiSe4O2 octahedra. Both Ti(5)-Se(3) bond lengths are 2.65 Å. Both Ti(5)-Se(7) bond lengths are 2.73 Å. The Ti(5)-O(5) bond length is 1.99 Å. The Ti(5)-O(8) bond length is 1.96 Å. In the sixth Ti site, Ti(6) is bonded in a distorted linear geometry to two equivalent Se(11), two equivalent Se(5), one O(3), and one O(9) atom. Both Ti(6)-Se(11) bond lengths are 2.72 Å. Both Ti(6)-Se(5) bond lengths are 2.72 Å. The Ti(6)-O(3) bond length is 1.96 Å. The Ti(6)-O(9) bond length is 1.95 Å. There are eighteen inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent La(12), two equivalent La(8), and one Ti(2) atom to form distorted SeLa4Ti trigonal bipyramids that share corners with two equivalent Se(14)La5 square pyramids,  a cornercorner with one O(6)La3Ti tetrahedra, corners with two equivalent O(2)La3Ti tetrahedra, corners with two equivalent O(9)La3Ti tetrahedra, corners with two equivalent Se(10)La5 trigonal bipyramids, edges with two equivalent Se(11)La4Ti2 pentagonal pyramids,  an edgeedge with one O(9)La3Ti tetrahedra,  an edgeedge with one Se(10)La5 trigonal bipyramid, edges with two equivalent Se(4)La3Ti2 trigonal bipyramids, and edges with two equivalent Se(1)La4Ti trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent La(4), two equivalent La(5), and one Ti(3) atom to form distorted SeLa4Ti trigonal bipyramids that share corners with two equivalent Se(6)La5 square pyramids,  a cornercorner with one O(10)La3Ti tetrahedra, corners with two equivalent O(3)La3Ti tetrahedra, corners with two equivalent O(7)La3Ti tetrahedra, corners with two equivalent Se(15)La5 trigonal bipyramids, edges with two equivalent Se(5)La4Ti2 pentagonal pyramids,  an edgeedge with one O(3)La3Ti tetrahedra,  an edgeedge with one Se(15)La5 trigonal bipyramid, edges with two equivalent Se(12)La3Ti2 trigonal bipyramids, and edges with two equivalent Se(2)La4Ti trigonal bipyramids. In the third Se site, Se(3) is bonded in a 6-coordinate geometry to two equivalent La(10), two equivalent La(6), and two equivalent Ti(5) atoms. In the fourth Se site, Se(4) is bonded to one La(11), one La(12), one La(9), and two equivalent Ti(2) atoms to form distorted SeLa3Ti2 trigonal bipyramids that share corners with two equivalent Se(7)La4Ti2 octahedra,  a cornercorner with one Se(11)La4Ti2 pentagonal pyramid,  a cornercorner with one Se(14)La5 square pyramid,  a cornercorner with one O(1)La3Ti tetrahedra,  a cornercorner with one O(4)La3Ti tetrahedra, corners with two equivalent O(5)La3Ti tetrahedra, corners with two equivalent O(8)La3Ti tetrahedra, corners with two equivalent Se(4)La3Ti2 trigonal bipyramids, edges with two equivalent O(6)La3Ti tetrahedra, edges with two equivalent Se(1)La4Ti trigonal bipyramids, and edges with two equivalent Se(10)La5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 58-61°. In the fifth Se site, Se(5) is bonded to one La(4), one La(5), two equivalent La(2), and two equivalent Ti(6) atoms to form distorted SeLa4Ti2 pentagonal pyramids that share corners with two equivalent Se(11)La4Ti2 pentagonal pyramids, corners with two equivalent Se(6)La5 square pyramids,  a cornercorner with one O(7)La3Ti tetrahedra, corners with two equivalent O(2)La3Ti tetrahedra,  a cornercorner with one Se(12)La3Ti2 trigonal bipyramid, corners with two equivalent Se(15)La5 trigonal bipyramids,  an edgeedge with one Se(11)La4Ti2 pentagonal pyramid, edges with two equivalent Se(5)La4Ti2 pentagonal pyramids,  an edgeedge with one O(2)La3Ti tetrahedra, edges with two equivalent O(3)La3Ti tetrahedra, edges with two equivalent O(9)La3Ti tetrahedra, edges with two equivalent Se(2)La4Ti trigonal bipyramids, and  a faceface with one Se(6)La5 square pyramid. In the sixth Se site, Se(6) is bonded to one La(4), two equivalent La(1), and two equivalent La(2) atoms to form distorted SeLa5 square pyramids that share corners with two equivalent Se(18)La4Ti2 octahedra, corners with two equivalent Se(5)La4Ti2 pentagonal pyramids, corners with two equivalent O(10)La3Ti tetrahedra, corners with two equivalent O(2)La3Ti tetrahedra, corners with two equivalent O(9)La3Ti tetrahedra,  a cornercorner with one Se(12)La3Ti2 trigonal bipyramid, corners with two equivalent Se(2)La4Ti trigonal bipyramids,  an edgeedge with one Se(18)La4Ti2 octahedra, edges with two equivalent Se(6)La5 square pyramids,  an edgeedge with one O(2)La3Ti tetrahedra, edges with two equivalent Se(15)La5 trigonal bipyramids, and  a faceface with one Se(5)La4Ti2 pentagonal pyramid. The corner-sharing octahedral tilt angles are 34°. In the seventh Se site, Se(7) is bonded to one La(11), one La(9), two equivalent La(7), and two equivalent Ti(5) atoms to form distorted SeLa4Ti2 octahedra that share corners with two equivalent Se(14)La5 square pyramids,  a cornercorner with one O(1)La3Ti tetrahedra,  a cornercorner with one O(4)La3Ti tetrahedra, corners with two equivalent Se(4)La3Ti2 trigonal bipyramids, edges with two equivalent Se(7)La4Ti2 octahedra,  an edgeedge with one Se(14)La5 square pyramid, edges with two equivalent O(5)La3Ti tetrahedra, edges with two equivalent O(6)La3Ti tetrahedra, edges with two equivalent O(8)La3Ti tetrahedra, and edges with two equivalent Se(10)La5 trigonal bipyramids. In the eighth Se site, Se(8) is bonded in a 5-coordinate geometry to one La(8), two equivalent La(7), and two equivalent Ti(2) atoms. In the ninth Se site, Se(9) is bonded in a 6-coordinate geometry to two equivalent La(11), two equivalent La(9), and two equivalent Ti(1) atoms. In the tenth Se site, Se(10) is bonded to one La(7), two equivalent La(11), and two equivalent La(12) atoms to form distorted SeLa5 trigonal bipyramids that share corners with two equivalent Se(11)La4Ti2 pentagonal pyramids,  a cornercorner with one O(6)La3Ti tetrahedra, corners with two equivalent O(4)La3Ti tetrahedra, corners with two equivalent O(5)La3Ti tetrahedra, corners with two equivalent Se(1)La4Ti trigonal bipyramids, edges with two equivalent Se(7)La4Ti2 octahedra, edges with two equivalent Se(14)La5 square pyramids,  an edgeedge with one O(5)La3Ti tetrahedra,  an edgeedge with one Se(1)La4Ti trigonal bipyramid, edges with two equivalent Se(4)La3Ti2 trigonal bipyramids, and edges with two equivalent Se(10)La5 trigonal bipyramids. In the eleventh Se site, Se(11) is bonded to one La(12), one La(8), two equivalent La(3), and two equivalent Ti(6) atoms to form distorted SeLa4Ti2 pentagonal pyramids that share corners with two equivalent Se(5)La4Ti2 pentagonal pyramids, corners with two equivalent Se(14)La5 square pyramids,  a cornercorner with one O(2)La3Ti tetrahedra, corners with two equivalent O(7)La3Ti tetrahedra,  a cornercorner with one Se(4)La3Ti2 trigonal bipyramid, corners with two equivalent Se(10)La5 trigonal bipyramids,  an edgeedge with one Se(5)La4Ti2 pentagonal pyramid, edges with two equivalent Se(11)La4Ti2 pentagonal pyramids,  an edgeedge with one O(7)La3Ti tetrahedra, edges with two equivalent O(3)La3Ti tetrahedra, edges with two equivalent O(9)La3Ti tetrahedra, edges with two equivalent Se(1)La4Ti trigonal bipyramids, and  a faceface with one Se(14)La5 square pyramid. In the twelfth Se site, Se(12) is bonded to one La(10), one La(4), one La(6), and two equivalent Ti(3) atoms to form distorted SeLa3Ti2 trigonal bipyramids that share corners with two equivalent Se(18)La4Ti2 octahedra,  a cornercorner with one Se(5)La4Ti2 pentagonal pyramid,  a cornercorner with one Se(6)La5 square pyramid,  a cornercorner with one O(5)La3Ti tetrahedra,  a cornercorner with one O(8)La3Ti tetrahedra, corners with two equivalent O(1)La3Ti tetrahedra, corners with two equivalent O(4)La3Ti tetrahedra, corners with two equivalent Se(12)La3Ti2 trigonal bipyramids, edges with two equivalent O(10)La3Ti tetrahedra, edges with two equivalent Se(2)La4Ti trigonal bipyramids, and edges with two equivalent Se(15)La5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 58-61°. In the thirteenth Se site, Se(13) is bonded in a distorted pentagonal planar geometry to one La(2), two equivalent La(5), and two equivalent Ti(4) atoms. In the fourteenth Se site, Se(14) is bonded to one La(12), two equivalent La(3), and two equivalent La(7) atoms to form SeLa5 square pyramids that share corners with two equivalent Se(7)La4Ti2 octahedra, corners with two equivalent Se(11)La4Ti2 pentagonal pyramids, corners with two equivalent O(3)La3Ti tetrahedra, corners with two equivalent O(6)La3Ti tetrahedra, corners with two equivalent O(7)La3Ti tetrahedra,  a cornercorner with one Se(4)La3Ti2 trigonal bipyramid, corners with two equivalent Se(1)La4Ti trigonal bipyramids,  an edgeedge with one Se(7)La4Ti2 octahedra, edges with two equivalent Se(14)La5 square pyramids,  an edgeedge with one O(7)La3Ti tetrahedra, edges with two equivalent Se(10)La5 trigonal bipyramids, and  a faceface with one Se(11)La4Ti2 pentagonal pyramid. The corner-sharing octahedral tilt angles are 33°. In the fifteenth Se site, Se(15) is bonded to one La(1), two equivalent La(10), and two equivalent La(4) atoms to form distorted SeLa5 trigonal bipyramids that share corners with two equivalent Se(5)La4Ti2 pentagonal pyramids,  a cornercorner with one O(10)La3Ti tetrahedra, corners with two equivalent O(4)La3Ti tetrahedra, corners with two equivalent O(5)La3Ti tetrahedra, corners with two equivalent Se(2)La4Ti trigonal bipyramids, edges with two equivalent Se(18)La4Ti2 octahedra, edges with two equivalent Se(6)La5 square pyramids,  an edgeedge with one O(4)La3Ti tetrahedra,  an edgeedge with one Se(2)La4Ti trigonal bipyramid, edges with two equivalent Se(12)La3Ti2 trigonal bipyramids, and edges with two equivalent Se(15)La5 trigonal bipyramids. In the sixteenth Se site, Se(16) is bonded in a 5-coordinate geometry to one La(5), two equivalent La(1), and two equivalent Ti(3) atoms. In the seventeenth Se site, Se(17) is bonded in a distorted pentagonal planar geometry to one La(3), two equivalent La(8), and two equivalent Ti(4) atoms. In the eighteenth Se site, Se(18) is bonded to one La(10), one La(6), two equivalent La(1), and two equivalent Ti(1) atoms to form distorted SeLa4Ti2 octahedra that share corners with two equivalent Se(6)La5 square pyramids,  a cornercorner with one O(5)La3Ti tetrahedra,  a cornercorner with one O(8)La3Ti tetrahedra, corners with two equivalent Se(12)La3Ti2 trigonal bipyramids, edges with two equivalent Se(18)La4Ti2 octahedra,  an edgeedge with one Se(6)La5 square pyramid, edges with two equivalent O(1)La3Ti tetrahedra, edges with two equivalent O(10)La3Ti tetrahedra, edges with two equivalent O(4)La3Ti tetrahedra, and edges with two equivalent Se(15)La5 trigonal bipyramids. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one La(9), two equivalent La(6), and one Ti(1) atom to form OLa3Ti tetrahedra that share  a cornercorner with one Se(7)La4Ti2 octahedra,  a cornercorner with one O(4)La3Ti tetrahedra, corners with two equivalent O(1)La3Ti tetrahedra, corners with two equivalent O(10)La3Ti tetrahedra, corners with two equivalent O(6)La3Ti tetrahedra,  a cornercorner with one Se(4)La3Ti2 trigonal bipyramid, corners with two equivalent Se(12)La3Ti2 trigonal bipyramids, edges with two equivalent Se(18)La4Ti2 octahedra,  an edgeedge with one O(10)La3Ti tetrahedra, and edges with two equivalent O(8)La3Ti tetrahedra. The corner-sharing octahedral tilt angles are 56°. In the second O site, O(2) is bonded to one La(8), two equivalent La(2), and one Ti(4) atom to form OLa3Ti tetrahedra that share  a cornercorner with one Se(11)La4Ti2 pentagonal pyramid, corners with two equivalent Se(5)La4Ti2 pentagonal pyramids, corners with two equivalent Se(6)La5 square pyramids,  a cornercorner with one O(7)La3Ti tetrahedra, corners with two equivalent O(2)La3Ti tetrahedra, corners with two equivalent Se(1)La4Ti trigonal bipyramids,  an edgeedge with one Se(5)La4Ti2 pentagonal pyramid,  an edgeedge with one Se(6)La5 square pyramid, and edges with two equivalent O(9)La3Ti tetrahedra. In the third O site, O(3) is bonded to one La(3), two equivalent La(5), and one Ti(6) atom to form OLa3Ti tetrahedra that share corners with two equivalent Se(14)La5 square pyramids,  a cornercorner with one O(9)La3Ti tetrahedra, corners with two equivalent O(3)La3Ti tetrahedra, corners with two equivalent Se(2)La4Ti trigonal bipyramids, edges with two equivalent Se(11)La4Ti2 pentagonal pyramids, edges with two equivalent Se(5)La4Ti2 pentagonal pyramids, edges with two equivalent O(7)La3Ti tetrahedra, and  an edgeedge with one Se(2)La4Ti trigonal bipyramid. In the fourth O site, O(4) is bonded to one La(11), two equivalent La(10), and one Ti(1) atom to form OLa3Ti tetrahedra that share  a cornercorner with one Se(7)La4Ti2 octahedra,  a cornercorner with one O(1)La3Ti tetrahedra, corners with two equivalent O(4)La3Ti tetrahedra,  a cornercorner with one Se(4)La3Ti2 trigonal bipyramid, corners with two equivalent Se(12)La3Ti2 trigonal bipyramids, corners with two equivalent Se(10)La5 trigonal bipyramids, corners with two equivalent Se(15)La5 trigonal bipyramids, edges with two equivalent Se(18)La4Ti2 octahedra, edges with two equivalent O(5)La3Ti tetrahedra, and  an edgeedge with one Se(15)La5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 59°. In the fifth O site, O(5) is bonded to one La(10), two equivalent La(11), and one Ti(5) atom to form OLa3Ti tetrahedra that share  a cornercorner with one Se(18)La4Ti2 octahedra,  a cornercorner with one O(8)La3Ti tetrahedra, corners with two equivalent O(5)La3Ti tetrahedra,  a cornercorner with one Se(12)La3Ti2 trigonal bipyramid, corners with two equivalent Se(4)La3Ti2 trigonal bipyramids, corners with two equivalent Se(10)La5 trigonal bipyramids, corners with two equivalent Se(15)La5 trigonal bipyramids, edges with two equivalent Se(7)La4Ti2 octahedra, edges with two equivalent O(4)La3Ti tetrahedra, and  an edgeedge with one Se(10)La5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 59°. In the sixth O site, O(6) is bonded to one La(7), two equivalent La(9), and one Ti(2) atom to form distorted OLa3Ti tetrahedra that share corners with two equivalent Se(14)La5 square pyramids, corners with two equivalent O(1)La3Ti tetrahedra, corners with two equivalent O(6)La3Ti tetrahedra, corners with two equivalent O(8)La3Ti tetrahedra,  a cornercorner with one Se(1)La4Ti trigonal bipyramid,  a cornercorner with one Se(10)La5 trigonal bipyramid, edges with two equivalent Se(7)La4Ti2 octahedra,  an edgeedge with one O(8)La3Ti tetrahedra, and edges with two equivalent Se(4)La3Ti2 trigonal bipyramids. In the seventh O site, O(7) is bonded to one La(5), two equivalent La(3), and one Ti(4) atom to form OLa3Ti tetrahedra that share  a cornercorner with one Se(5)La4Ti2 pentagonal pyramid, corners with two equivalent Se(11)La4Ti2 pentagonal pyramids, corners with two equivalent Se(14)La5 square pyramids,  a cornercorner with one O(2)La3Ti tetrahedra, corners with two equivalent O(7)La3Ti tetrahedra, corners with two equivalent Se(2)La4Ti trigonal bipyramids,  an edgeedge with one Se(11)La4Ti2 pentagonal pyramid,  an edgeedge with one Se(14)La5 square pyramid, and edges with two equivalent O(3)La3Ti tetrahedra. In the eighth O site, O(8) is bonded to one La(6), two equivalent La(9), and one Ti(5) atom to form OLa3Ti tetrahedra that share  a cornercorner with one Se(18)La4Ti2 octahedra,  a cornercorner with one O(5)La3Ti tetrahedra, corners with two equivalent O(10)La3Ti tetrahedra, corners with two equivalent O(6)La3Ti tetrahedra, corners with two equivalent O(8)La3Ti tetrahedra,  a cornercorner with one Se(12)La3Ti2 trigonal bipyramid, corners with two equivalent Se(4)La3Ti2 trigonal bipyramids, edges with two equivalent Se(7)La4Ti2 octahedra,  an edgeedge with one O(6)La3Ti tetrahedra, and edges with two equivalent O(1)La3Ti tetrahedra. The corner-sharing octahedral tilt angles are 56°. In the ninth O site, O(9) is bonded to one La(2), two equivalent La(8), and one Ti(6) atom to form OLa3Ti tetrahedra that share corners with two equivalent Se(6)La5 square pyramids,  a cornercorner with one O(3)La3Ti tetrahedra, corners with two equivalent O(9)La3Ti tetrahedra, corners with two equivalent Se(1)La4Ti trigonal bipyramids, edges with two equivalent Se(11)La4Ti2 pentagonal pyramids, edges with two equivalent Se(5)La4Ti2 pentagonal pyramids, edges with two equivalent O(2)La3Ti tetrahedra, and  an edgeedge with one Se(1)La4Ti trigonal bipyramid. In the tenth O site, O(10) is bonded to one La(1), two equivalent La(6), and one Ti(3) atom to form distorted OLa3Ti tetrahedra that share corners with two equivalent Se(6)La5 square pyramids, corners with two equivalent O(1)La3Ti tetrahedra, corners with two equivalent O(10)La3Ti tetrahedra, corners with two equivalent O(8)La3Ti tetrahedra,  a cornercorner with one Se(2)La4Ti trigonal bipyramid,  a cornercorner with one Se(15)La5 trigonal bipyramid, edges with two equivalent Se(18)La4Ti2 octahedra,  an edgeedge with one O(1)La3Ti tetrahedra, and edges with two equivalent Se(12)La3Ti2 trigonal bipyramids.