La4FeSe6O crystallizes in the triclinic P1 space group. There are sixteen inequivalent La sites. In the first La site, La(1) is bonded in a 1-coordinate geometry to one Se(1), one Se(13), one Se(17), one Se(20), one Se(22), one Se(24), one Se(3), one Se(7), and one O(3) atom. In the second La site, La(2) is bonded in a 1-coordinate geometry to one Se(14), one Se(18), one Se(19), one Se(2), one Se(21), one Se(23), one Se(4), one Se(8), and one O(4) atom. In the third La site, La(3) is bonded in a 1-coordinate geometry to one Se(11), one Se(13), one Se(15), one Se(17), one Se(19), one Se(21), one Se(23), one Se(5), one Se(9), and one O(2) atom. In the fourth La site, La(4) is bonded in a 1-coordinate geometry to one Se(10), one Se(12), one Se(14), one Se(16), one Se(18), one Se(20), one Se(6), and one O(1) atom. In the fifth La site, La(5) is bonded in a distorted single-bond geometry to one Se(12), one Se(13), one Se(15), one Se(20), one Se(24), one Se(3), one Se(7), and one O(1) atom. In the sixth La site, La(6) is bonded in a distorted single-bond geometry to one Se(11), one Se(14), one Se(16), one Se(19), one Se(23), one Se(4), one Se(8), and one O(2) atom. In the seventh La site, La(7) is bonded in a distorted single-bond geometry to one Se(1), one Se(10), one Se(13), one Se(17), one Se(22), one Se(24), one Se(3), and one O(1) atom. In the eighth La site, La(8) is bonded in a distorted single-bond geometry to one Se(14), one Se(18), one Se(2), one Se(21), one Se(23), one Se(4), one Se(9), and one O(2) atom. In the ninth La site, La(9) is bonded in a distorted single-bond geometry to one Se(11), one Se(15), one Se(17), one Se(19), one Se(21), one Se(3), one Se(9), and one O(3) atom. In the tenth La site, La(10) is bonded in a distorted single-bond geometry to one Se(10), one Se(12), one Se(16), one Se(18), one Se(20), one Se(22), one Se(4), and one O(4) atom. In the eleventh La site, La(11) is bonded in a distorted single-bond geometry to one Se(11), one Se(13), one Se(17), one Se(21), one Se(23), one Se(5), one Se(7), and one O(3) atom. In the twelfth La site, La(12) is bonded in a distorted single-bond geometry to one Se(12), one Se(14), one Se(18), one Se(22), one Se(24), one Se(6), one Se(8), and one O(4) atom. In the thirteenth La site, La(13) is bonded in a distorted single-bond geometry to one Se(1), one Se(13), one Se(15), one Se(19), one Se(23), one Se(5), one Se(9), and one O(3) atom. In the fourteenth La site, La(14) is bonded in a distorted single-bond geometry to one Se(10), one Se(14), one Se(16), one Se(2), one Se(20), one Se(24), one Se(6), and one O(4) atom. In the fifteenth La site, La(15) is bonded in a distorted single-bond geometry to one Se(1), one Se(15), one Se(17), one Se(20), one Se(22), one Se(6), one Se(7), and one O(1) atom. In the sixteenth La site, La(16) is bonded in a distorted single-bond geometry to one Se(16), one Se(18), one Se(19), one Se(2), one Se(21), one Se(5), one Se(8), and one O(2) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one Se(1), one Se(10), one Se(12), one Se(3), one Se(6), and one Se(7) atom to form distorted face-sharing FeSe6 octahedra. In the second Fe site, Fe(2) is bonded to one Se(10), one Se(12), one Se(2), one Se(4), one Se(6), and one Se(8) atom to form distorted face-sharing FeSe6 octahedra. In the third Fe site, Fe(3) is bonded to one Se(11), one Se(2), one Se(4), one Se(5), one Se(8), and one Se(9) atom to form distorted face-sharing FeSe6 octahedra. In the fourth Fe site, Fe(4) is bonded to one Se(1), one Se(11), one Se(3), one Se(5), one Se(7), and one Se(9) atom to form distorted face-sharing FeSe6 octahedra. There are twenty-four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to one La(1), one La(13), one La(15), one La(7), one Fe(1), and one Fe(4) atom. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to one La(14), one La(16), one La(2), one La(8), one Fe(2), and one Fe(3) atom. In the third Se site, Se(3) is bonded in a 6-coordinate geometry to one La(1), one La(5), one La(7), one La(9), one Fe(1), and one Fe(4) atom. In the fourth Se site, Se(4) is bonded in a 6-coordinate geometry to one La(10), one La(2), one La(6), one La(8), one Fe(2), and one Fe(3) atom. In the fifth Se site, Se(5) is bonded in a 6-coordinate geometry to one La(11), one La(13), one La(16), one La(3), one Fe(3), and one Fe(4) atom. In the sixth Se site, Se(6) is bonded in a 6-coordinate geometry to one La(12), one La(14), one La(15), one La(4), one Fe(1), and one Fe(2) atom. In the seventh Se site, Se(7) is bonded in a 6-coordinate geometry to one La(1), one La(11), one La(15), one La(5), one Fe(1), and one Fe(4) atom. In the eighth Se site, Se(8) is bonded in a 6-coordinate geometry to one La(12), one La(16), one La(2), one La(6), one Fe(2), and one Fe(3) atom. In the ninth Se site, Se(9) is bonded in a 6-coordinate geometry to one La(13), one La(3), one La(8), one La(9), one Fe(3), and one Fe(4) atom. In the tenth Se site, Se(10) is bonded in a 6-coordinate geometry to one La(10), one La(14), one La(4), one La(7), one Fe(1), and one Fe(2) atom. In the eleventh Se site, Se(11) is bonded in a 6-coordinate geometry to one La(11), one La(3), one La(6), one La(9), one Fe(3), and one Fe(4) atom. In the twelfth Se site, Se(12) is bonded in a 6-coordinate geometry to one La(10), one La(12), one La(4), one La(5), one Fe(1), and one Fe(2) atom. In the thirteenth Se site, Se(13) is bonded in a 6-coordinate geometry to one La(1), one La(11), one La(13), one La(3), one La(5), and one La(7) atom. In the fourteenth Se site, Se(14) is bonded in a 6-coordinate geometry to one La(12), one La(14), one La(2), one La(4), one La(6), and one La(8) atom. In the fifteenth Se site, Se(15) is bonded in a 5-coordinate geometry to one La(13), one La(15), one La(3), one La(5), and one La(9) atom. In the sixteenth Se site, Se(16) is bonded in a 5-coordinate geometry to one La(10), one La(14), one La(16), one La(4), and one La(6) atom. In the seventeenth Se site, Se(17) is bonded in a 6-coordinate geometry to one La(1), one La(11), one La(15), one La(3), one La(7), and one La(9) atom. In the eighteenth Se site, Se(18) is bonded in a 6-coordinate geometry to one La(10), one La(12), one La(16), one La(2), one La(4), and one La(8) atom. In the nineteenth Se site, Se(19) is bonded in a 6-coordinate geometry to one La(13), one La(16), one La(2), one La(3), one La(6), and one La(9) atom. In the twentieth Se site, Se(20) is bonded in a 6-coordinate geometry to one La(1), one La(10), one La(14), one La(15), one La(4), and one La(5) atom. In the twenty-first Se site, Se(21) is bonded in a 6-coordinate geometry to one La(11), one La(16), one La(2), one La(3), one La(8), and one La(9) atom. In the twenty-second Se site, Se(22) is bonded in a 5-coordinate geometry to one La(1), one La(10), one La(12), one La(15), and one La(7) atom. In the twenty-third Se site, Se(23) is bonded in a 6-coordinate geometry to one La(11), one La(13), one La(2), one La(3), one La(6), and one La(8) atom. In the twenty-fourth Se site, Se(24) is bonded in a 5-coordinate geometry to one La(1), one La(12), one La(14), one La(5), and one La(7) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a tetrahedral geometry to one La(15), one La(4), one La(5), and one La(7) atom. In the second O site, O(2) is bonded in a tetrahedral geometry to one La(16), one La(3), one La(6), and one La(8) atom. In the third O site, O(3) is bonded in a tetrahedral geometry to one La(1), one La(11), one La(13), and one La(9) atom. In the fourth O site, O(4) is bonded in a tetrahedral geometry to one La(10), one La(12), one La(14), and one La(2) atom.
La4FeSe6O crystallizes in the triclinic P1 space group. There are sixteen inequivalent La sites. In the first La site, La(1) is bonded in a 1-coordinate geometry to one Se(1), one Se(13), one Se(17), one Se(20), one Se(22), one Se(24), one Se(3), one Se(7), and one O(3) atom. The La(1)-Se(1) bond length is 3.61 Å. The La(1)-Se(13) bond length is 3.73 Å. The La(1)-Se(17) bond length is 3.72 Å. The La(1)-Se(20) bond length is 2.97 Å. The La(1)-Se(22) bond length is 2.98 Å. The La(1)-Se(24) bond length is 2.98 Å. The La(1)-Se(3) bond length is 3.56 Å. The La(1)-Se(7) bond length is 3.56 Å. The La(1)-O(3) bond length is 2.39 Å. In the second La site, La(2) is bonded in a 1-coordinate geometry to one Se(14), one Se(18), one Se(19), one Se(2), one Se(21), one Se(23), one Se(4), one Se(8), and one O(4) atom. The La(2)-Se(14) bond length is 3.74 Å. The La(2)-Se(18) bond length is 3.70 Å. The La(2)-Se(19) bond length is 2.98 Å. The La(2)-Se(2) bond length is 3.63 Å. The La(2)-Se(21) bond length is 2.97 Å. The La(2)-Se(23) bond length is 2.97 Å. The La(2)-Se(4) bond length is 3.61 Å. The La(2)-Se(8) bond length is 3.52 Å. The La(2)-O(4) bond length is 2.39 Å. In the third La site, La(3) is bonded in a 1-coordinate geometry to one Se(11), one Se(13), one Se(15), one Se(17), one Se(19), one Se(21), one Se(23), one Se(5), one Se(9), and one O(2) atom. The La(3)-Se(11) bond length is 3.69 Å. The La(3)-Se(13) bond length is 2.97 Å. The La(3)-Se(15) bond length is 2.98 Å. The La(3)-Se(17) bond length is 2.96 Å. The La(3)-Se(19) bond length is 3.78 Å. The La(3)-Se(21) bond length is 3.72 Å. The La(3)-Se(23) bond length is 3.74 Å. The La(3)-Se(5) bond length is 3.62 Å. The La(3)-Se(9) bond length is 3.52 Å. The La(3)-O(2) bond length is 2.39 Å. In the fourth La site, La(4) is bonded in a 1-coordinate geometry to one Se(10), one Se(12), one Se(14), one Se(16), one Se(18), one Se(20), one Se(6), and one O(1) atom. The La(4)-Se(10) bond length is 3.59 Å. The La(4)-Se(12) bond length is 3.57 Å. The La(4)-Se(14) bond length is 2.98 Å. The La(4)-Se(16) bond length is 2.98 Å. The La(4)-Se(18) bond length is 2.97 Å. The La(4)-Se(20) bond length is 3.74 Å. The La(4)-Se(6) bond length is 3.57 Å. The La(4)-O(1) bond length is 2.39 Å. In the fifth La site, La(5) is bonded in a distorted single-bond geometry to one Se(12), one Se(13), one Se(15), one Se(20), one Se(24), one Se(3), one Se(7), and one O(1) atom. The La(5)-Se(12) bond length is 3.09 Å. The La(5)-Se(13) bond length is 3.06 Å. The La(5)-Se(15) bond length is 3.06 Å. The La(5)-Se(20) bond length is 3.35 Å. The La(5)-Se(24) bond length is 3.32 Å. The La(5)-Se(3) bond length is 3.06 Å. The La(5)-Se(7) bond length is 3.05 Å. The La(5)-O(1) bond length is 2.42 Å. In the sixth La site, La(6) is bonded in a distorted single-bond geometry to one Se(11), one Se(14), one Se(16), one Se(19), one Se(23), one Se(4), one Se(8), and one O(2) atom. The La(6)-Se(11) bond length is 3.12 Å. The La(6)-Se(14) bond length is 3.07 Å. The La(6)-Se(16) bond length is 3.06 Å. The La(6)-Se(19) bond length is 3.34 Å. The La(6)-Se(23) bond length is 3.30 Å. The La(6)-Se(4) bond length is 3.05 Å. The La(6)-Se(8) bond length is 3.06 Å. The La(6)-O(2) bond length is 2.42 Å. In the seventh La site, La(7) is bonded in a distorted single-bond geometry to one Se(1), one Se(10), one Se(13), one Se(17), one Se(22), one Se(24), one Se(3), and one O(1) atom. The La(7)-Se(1) bond length is 3.06 Å. The La(7)-Se(10) bond length is 3.09 Å. The La(7)-Se(13) bond length is 3.08 Å. The La(7)-Se(17) bond length is 3.07 Å. The La(7)-Se(22) bond length is 3.31 Å. The La(7)-Se(24) bond length is 3.32 Å. The La(7)-Se(3) bond length is 3.07 Å. The La(7)-O(1) bond length is 2.42 Å. In the eighth La site, La(8) is bonded in a distorted single-bond geometry to one Se(14), one Se(18), one Se(2), one Se(21), one Se(23), one Se(4), one Se(9), and one O(2) atom. The La(8)-Se(14) bond length is 3.06 Å. The La(8)-Se(18) bond length is 3.07 Å. The La(8)-Se(2) bond length is 3.05 Å. The La(8)-Se(21) bond length is 3.30 Å. The La(8)-Se(23) bond length is 3.34 Å. The La(8)-Se(4) bond length is 3.06 Å. The La(8)-Se(9) bond length is 3.08 Å. The La(8)-O(2) bond length is 2.42 Å. In the ninth La site, La(9) is bonded in a distorted single-bond geometry to one Se(11), one Se(15), one Se(17), one Se(19), one Se(21), one Se(3), one Se(9), and one O(3) atom. The La(9)-Se(11) bond length is 3.06 Å. The La(9)-Se(15) bond length is 3.32 Å. The La(9)-Se(17) bond length is 3.34 Å. The La(9)-Se(19) bond length is 3.07 Å. The La(9)-Se(21) bond length is 3.06 Å. The La(9)-Se(3) bond length is 3.09 Å. The La(9)-Se(9) bond length is 3.05 Å. The La(9)-O(3) bond length is 2.42 Å. In the tenth La site, La(10) is bonded in a distorted single-bond geometry to one Se(10), one Se(12), one Se(16), one Se(18), one Se(20), one Se(22), one Se(4), and one O(4) atom. The La(10)-Se(10) bond length is 3.06 Å. The La(10)-Se(12) bond length is 3.06 Å. The La(10)-Se(16) bond length is 3.30 Å. The La(10)-Se(18) bond length is 3.34 Å. The La(10)-Se(20) bond length is 3.08 Å. The La(10)-Se(22) bond length is 3.06 Å. The La(10)-Se(4) bond length is 3.12 Å. The La(10)-O(4) bond length is 2.41 Å. In the eleventh La site, La(11) is bonded in a distorted single-bond geometry to one Se(11), one Se(13), one Se(17), one Se(21), one Se(23), one Se(5), one Se(7), and one O(3) atom. The La(11)-Se(11) bond length is 3.06 Å. The La(11)-Se(13) bond length is 3.33 Å. The La(11)-Se(17) bond length is 3.31 Å. The La(11)-Se(21) bond length is 3.06 Å. The La(11)-Se(23) bond length is 3.07 Å. The La(11)-Se(5) bond length is 3.06 Å. The La(11)-Se(7) bond length is 3.10 Å. The La(11)-O(3) bond length is 2.42 Å. In the twelfth La site, La(12) is bonded in a distorted single-bond geometry to one Se(12), one Se(14), one Se(18), one Se(22), one Se(24), one Se(6), one Se(8), and one O(4) atom. The La(12)-Se(12) bond length is 3.06 Å. The La(12)-Se(14) bond length is 3.32 Å. The La(12)-Se(18) bond length is 3.35 Å. The La(12)-Se(22) bond length is 3.06 Å. The La(12)-Se(24) bond length is 3.07 Å. The La(12)-Se(6) bond length is 3.06 Å. The La(12)-Se(8) bond length is 3.07 Å. The La(12)-O(4) bond length is 2.42 Å. In the thirteenth La site, La(13) is bonded in a distorted single-bond geometry to one Se(1), one Se(13), one Se(15), one Se(19), one Se(23), one Se(5), one Se(9), and one O(3) atom. The La(13)-Se(1) bond length is 3.11 Å. The La(13)-Se(13) bond length is 3.35 Å. The La(13)-Se(15) bond length is 3.31 Å. The La(13)-Se(19) bond length is 3.06 Å. The La(13)-Se(23) bond length is 3.06 Å. The La(13)-Se(5) bond length is 3.06 Å. The La(13)-Se(9) bond length is 3.06 Å. The La(13)-O(3) bond length is 2.41 Å. In the fourteenth La site, La(14) is bonded in a distorted single-bond geometry to one Se(10), one Se(14), one Se(16), one Se(2), one Se(20), one Se(24), one Se(6), and one O(4) atom. The La(14)-Se(10) bond length is 3.06 Å. The La(14)-Se(14) bond length is 3.32 Å. The La(14)-Se(16) bond length is 3.31 Å. The La(14)-Se(2) bond length is 3.12 Å. The La(14)-Se(20) bond length is 3.07 Å. The La(14)-Se(24) bond length is 3.07 Å. The La(14)-Se(6) bond length is 3.06 Å. The La(14)-O(4) bond length is 2.42 Å. In the fifteenth La site, La(15) is bonded in a distorted single-bond geometry to one Se(1), one Se(15), one Se(17), one Se(20), one Se(22), one Se(6), one Se(7), and one O(1) atom. The La(15)-Se(1) bond length is 3.06 Å. The La(15)-Se(15) bond length is 3.07 Å. The La(15)-Se(17) bond length is 3.06 Å. The La(15)-Se(20) bond length is 3.34 Å. The La(15)-Se(22) bond length is 3.31 Å. The La(15)-Se(6) bond length is 3.11 Å. The La(15)-Se(7) bond length is 3.06 Å. The La(15)-O(1) bond length is 2.41 Å. In the sixteenth La site, La(16) is bonded in a distorted single-bond geometry to one Se(16), one Se(18), one Se(19), one Se(2), one Se(21), one Se(5), one Se(8), and one O(2) atom. The La(16)-Se(16) bond length is 3.07 Å. The La(16)-Se(18) bond length is 3.08 Å. The La(16)-Se(19) bond length is 3.37 Å. The La(16)-Se(2) bond length is 3.04 Å. The La(16)-Se(21) bond length is 3.29 Å. The La(16)-Se(5) bond length is 3.08 Å. The La(16)-Se(8) bond length is 3.06 Å. The La(16)-O(2) bond length is 2.42 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one Se(1), one Se(10), one Se(12), one Se(3), one Se(6), and one Se(7) atom to form distorted face-sharing FeSe6 octahedra. The Fe(1)-Se(1) bond length is 2.81 Å. The Fe(1)-Se(10) bond length is 2.69 Å. The Fe(1)-Se(12) bond length is 2.67 Å. The Fe(1)-Se(3) bond length is 2.81 Å. The Fe(1)-Se(6) bond length is 2.71 Å. The Fe(1)-Se(7) bond length is 2.88 Å. In the second Fe site, Fe(2) is bonded to one Se(10), one Se(12), one Se(2), one Se(4), one Se(6), and one Se(8) atom to form distorted face-sharing FeSe6 octahedra. The Fe(2)-Se(10) bond length is 2.80 Å. The Fe(2)-Se(12) bond length is 2.89 Å. The Fe(2)-Se(2) bond length is 2.68 Å. The Fe(2)-Se(4) bond length is 2.67 Å. The Fe(2)-Se(6) bond length is 2.82 Å. The Fe(2)-Se(8) bond length is 2.68 Å. In the third Fe site, Fe(3) is bonded to one Se(11), one Se(2), one Se(4), one Se(5), one Se(8), and one Se(9) atom to form distorted face-sharing FeSe6 octahedra. The Fe(3)-Se(11) bond length is 2.64 Å. The Fe(3)-Se(2) bond length is 2.71 Å. The Fe(3)-Se(4) bond length is 2.80 Å. The Fe(3)-Se(5) bond length is 2.65 Å. The Fe(3)-Se(8) bond length is 2.90 Å. The Fe(3)-Se(9) bond length is 2.74 Å. In the fourth Fe site, Fe(4) is bonded to one Se(1), one Se(11), one Se(3), one Se(5), one Se(7), and one Se(9) atom to form distorted face-sharing FeSe6 octahedra. The Fe(4)-Se(1) bond length is 2.69 Å. The Fe(4)-Se(11) bond length is 2.79 Å. The Fe(4)-Se(3) bond length is 2.69 Å. The Fe(4)-Se(5) bond length is 2.84 Å. The Fe(4)-Se(7) bond length is 2.69 Å. The Fe(4)-Se(9) bond length is 2.81 Å. There are twenty-four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to one La(1), one La(13), one La(15), one La(7), one Fe(1), and one Fe(4) atom. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to one La(14), one La(16), one La(2), one La(8), one Fe(2), and one Fe(3) atom. In the third Se site, Se(3) is bonded in a 6-coordinate geometry to one La(1), one La(5), one La(7), one La(9), one Fe(1), and one Fe(4) atom. In the fourth Se site, Se(4) is bonded in a 6-coordinate geometry to one La(10), one La(2), one La(6), one La(8), one Fe(2), and one Fe(3) atom. In the fifth Se site, Se(5) is bonded in a 6-coordinate geometry to one La(11), one La(13), one La(16), one La(3), one Fe(3), and one Fe(4) atom. In the sixth Se site, Se(6) is bonded in a 6-coordinate geometry to one La(12), one La(14), one La(15), one La(4), one Fe(1), and one Fe(2) atom. In the seventh Se site, Se(7) is bonded in a 6-coordinate geometry to one La(1), one La(11), one La(15), one La(5), one Fe(1), and one Fe(4) atom. In the eighth Se site, Se(8) is bonded in a 6-coordinate geometry to one La(12), one La(16), one La(2), one La(6), one Fe(2), and one Fe(3) atom. In the ninth Se site, Se(9) is bonded in a 6-coordinate geometry to one La(13), one La(3), one La(8), one La(9), one Fe(3), and one Fe(4) atom. In the tenth Se site, Se(10) is bonded in a 6-coordinate geometry to one La(10), one La(14), one La(4), one La(7), one Fe(1), and one Fe(2) atom. In the eleventh Se site, Se(11) is bonded in a 6-coordinate geometry to one La(11), one La(3), one La(6), one La(9), one Fe(3), and one Fe(4) atom. In the twelfth Se site, Se(12) is bonded in a 6-coordinate geometry to one La(10), one La(12), one La(4), one La(5), one Fe(1), and one Fe(2) atom. In the thirteenth Se site, Se(13) is bonded in a 6-coordinate geometry to one La(1), one La(11), one La(13), one La(3), one La(5), and one La(7) atom. In the fourteenth Se site, Se(14) is bonded in a 6-coordinate geometry to one La(12), one La(14), one La(2), one La(4), one La(6), and one La(8) atom. In the fifteenth Se site, Se(15) is bonded in a 5-coordinate geometry to one La(13), one La(15), one La(3), one La(5), and one La(9) atom. In the sixteenth Se site, Se(16) is bonded in a 5-coordinate geometry to one La(10), one La(14), one La(16), one La(4), and one La(6) atom. In the seventeenth Se site, Se(17) is bonded in a 6-coordinate geometry to one La(1), one La(11), one La(15), one La(3), one La(7), and one La(9) atom. In the eighteenth Se site, Se(18) is bonded in a 6-coordinate geometry to one La(10), one La(12), one La(16), one La(2), one La(4), and one La(8) atom. In the nineteenth Se site, Se(19) is bonded in a 6-coordinate geometry to one La(13), one La(16), one La(2), one La(3), one La(6), and one La(9) atom. In the twentieth Se site, Se(20) is bonded in a 6-coordinate geometry to one La(1), one La(10), one La(14), one La(15), one La(4), and one La(5) atom. In the twenty-first Se site, Se(21) is bonded in a 6-coordinate geometry to one La(11), one La(16), one La(2), one La(3), one La(8), and one La(9) atom. In the twenty-second Se site, Se(22) is bonded in a 5-coordinate geometry to one La(1), one La(10), one La(12), one La(15), and one La(7) atom. In the twenty-third Se site, Se(23) is bonded in a 6-coordinate geometry to one La(11), one La(13), one La(2), one La(3), one La(6), and one La(8) atom. In the twenty-fourth Se site, Se(24) is bonded in a 5-coordinate geometry to one La(1), one La(12), one La(14), one La(5), and one La(7) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a tetrahedral geometry to one La(15), one La(4), one La(5), and one La(7) atom. In the second O site, O(2) is bonded in a tetrahedral geometry to one La(16), one La(3), one La(6), and one La(8) atom. In the third O site, O(3) is bonded in a tetrahedral geometry to one La(1), one La(11), one La(13), and one La(9) atom. In the fourth O site, O(4) is bonded in a tetrahedral geometry to one La(10), one La(12), one La(14), and one La(2) atom.