La12Mn3(AlSe7)4 crystallizes in the triclinic P1 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(13), one Se(15), one Se(18), one Se(19), one Se(27), one Se(28), one Se(4), and one Se(7) atom. In the second La site, La(2) is bonded in a 8-coordinate geometry to one Se(14), one Se(16), one Se(17), one Se(20), one Se(27), one Se(28), one Se(3), and one Se(8) atom. In the third La site, La(3) is bonded in a 8-coordinate geometry to one Se(10), one Se(11), one Se(15), one Se(20), one Se(22), one Se(23), one Se(24), and one Se(4) atom. In the fourth La site, La(4) is bonded in a 8-coordinate geometry to one Se(12), one Se(16), one Se(19), one Se(21), one Se(23), one Se(24), one Se(3), and one Se(9) atom. In the fifth La site, La(5) is bonded in a 8-coordinate geometry to one Se(11), one Se(13), one Se(18), one Se(21), one Se(25), one Se(26), one Se(4), and one Se(6) atom. In the sixth La site, La(6) is bonded in a 8-coordinate geometry to one Se(12), one Se(14), one Se(17), one Se(22), one Se(25), one Se(26), one Se(3), and one Se(5) atom. In the seventh La site, La(7) is bonded in a 8-coordinate geometry to one Se(10), one Se(13), one Se(2), one Se(21), one Se(22), one Se(24), one Se(25), and one Se(8) atom. In the eighth La site, La(8) is bonded in a 8-coordinate geometry to one Se(1), one Se(14), one Se(21), one Se(22), one Se(23), one Se(26), one Se(7), and one Se(9) atom. In the ninth La site, La(9) is bonded in a 8-coordinate geometry to one Se(10), one Se(16), one Se(17), one Se(18), one Se(2), one Se(26), one Se(28), and one Se(6) atom. In the tenth La site, La(10) is bonded in a 8-coordinate geometry to one Se(1), one Se(15), one Se(17), one Se(18), one Se(25), one Se(27), one Se(5), and one Se(9) atom. In the eleventh La site, La(11) is bonded in a 8-coordinate geometry to one Se(12), one Se(19), one Se(2), one Se(20), one Se(24), one Se(27), one Se(6), and one Se(8) atom. In the twelfth La site, La(12) is bonded in a 8-coordinate geometry to one Se(1), one Se(11), one Se(19), one Se(20), one Se(23), one Se(28), one Se(5), and one Se(7) atom. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one Se(18), one Se(19), one Se(21), one Se(23), one Se(26), and one Se(28) atom to form face-sharing MnSe6 octahedra. In the second Mn site, Mn(2) is bonded to one Se(17), one Se(20), one Se(22), one Se(24), one Se(25), and one Se(27) atom to form face-sharing MnSe6 octahedra. In the third Mn site, Mn(3) is bonded to one Se(18), one Se(19), one Se(21), one Se(24), one Se(25), and one Se(27) atom to form face-sharing MnSe6 octahedra. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a tetrahedral geometry to one Se(2), one Se(5), one Se(7), and one Se(9) atom. In the second Al site, Al(2) is bonded in a tetrahedral geometry to one Se(1), one Se(10), one Se(6), and one Se(8) atom. In the third Al site, Al(3) is bonded in a tetrahedral geometry to one Se(11), one Se(13), one Se(15), and one Se(3) atom. In the fourth Al site, Al(4) is bonded in a tetrahedral geometry to one Se(12), one Se(14), one Se(16), and one Se(4) atom. There are twenty-eight inequivalent Se sites. In the first Se site, Se(1) is bonded to one La(10), one La(12), one La(8), and one Al(2) atom to form corner-sharing SeLa3Al tetrahedra. In the second Se site, Se(2) is bonded to one La(11), one La(7), one La(9), and one Al(1) atom to form corner-sharing SeLa3Al tetrahedra. In the third Se site, Se(3) is bonded to one La(2), one La(4), one La(6), and one Al(3) atom to form corner-sharing SeLa3Al tetrahedra. In the fourth Se site, Se(4) is bonded to one La(1), one La(3), one La(5), and one Al(4) atom to form corner-sharing SeLa3Al tetrahedra. In the fifth Se site, Se(5) is bonded in a distorted rectangular see-saw-like geometry to one La(10), one La(12), one La(6), and one Al(1) atom. In the sixth Se site, Se(6) is bonded in a rectangular see-saw-like geometry to one La(11), one La(5), one La(9), and one Al(2) atom. In the seventh Se site, Se(7) is bonded in a distorted rectangular see-saw-like geometry to one La(1), one La(12), one La(8), and one Al(1) atom. In the eighth Se site, Se(8) is bonded in a distorted rectangular see-saw-like geometry to one La(11), one La(2), one La(7), and one Al(2) atom. In the ninth Se site, Se(9) is bonded in a distorted rectangular see-saw-like geometry to one La(10), one La(4), one La(8), and one Al(1) atom. In the tenth Se site, Se(10) is bonded in a distorted rectangular see-saw-like geometry to one La(3), one La(7), one La(9), and one Al(2) atom. In the eleventh Se site, Se(11) is bonded in a distorted rectangular see-saw-like geometry to one La(12), one La(3), one La(5), and one Al(3) atom. In the twelfth Se site, Se(12) is bonded in a distorted rectangular see-saw-like geometry to one La(11), one La(4), one La(6), and one Al(4) atom. In the thirteenth Se site, Se(13) is bonded in a distorted rectangular see-saw-like geometry to one La(1), one La(5), one La(7), and one Al(3) atom. In the fourteenth Se site, Se(14) is bonded in a distorted rectangular see-saw-like geometry to one La(2), one La(6), one La(8), and one Al(4) atom. In the fifteenth Se site, Se(15) is bonded in a distorted rectangular see-saw-like geometry to one La(1), one La(10), one La(3), and one Al(3) atom. In the sixteenth Se site, Se(16) is bonded in a distorted rectangular see-saw-like geometry to one La(2), one La(4), one La(9), and one Al(4) atom. In the seventeenth Se site, Se(17) is bonded to one La(10), one La(2), one La(6), one La(9), and one Mn(2) atom to form distorted SeLa4Mn trigonal bipyramids that share  a cornercorner with one Se(1)La3Al tetrahedra,  a cornercorner with one Se(2)La3Al tetrahedra, corners with two equivalent Se(3)La3Al tetrahedra,  an edgeedge with one Se(20)La4Mn trigonal bipyramid, and  an edgeedge with one Se(22)La4Mn trigonal bipyramid. In the eighteenth Se site, Se(18) is bonded in a 6-coordinate geometry to one La(1), one La(10), one La(5), one La(9), one Mn(1), and one Mn(3) atom. In the nineteenth Se site, Se(19) is bonded in a 6-coordinate geometry to one La(1), one La(11), one La(12), one La(4), one Mn(1), and one Mn(3) atom. In the twentieth Se site, Se(20) is bonded to one La(11), one La(12), one La(2), one La(3), and one Mn(2) atom to form distorted SeLa4Mn trigonal bipyramids that share  a cornercorner with one Se(1)La3Al tetrahedra,  a cornercorner with one Se(2)La3Al tetrahedra,  a cornercorner with one Se(3)La3Al tetrahedra,  a cornercorner with one Se(4)La3Al tetrahedra,  an edgeedge with one Se(17)La4Mn trigonal bipyramid, and  an edgeedge with one Se(22)La4Mn trigonal bipyramid. In the twenty-first Se site, Se(21) is bonded in a 6-coordinate geometry to one La(4), one La(5), one La(7), one La(8), one Mn(1), and one Mn(3) atom. In the twenty-second Se site, Se(22) is bonded to one La(3), one La(6), one La(7), one La(8), and one Mn(2) atom to form distorted SeLa4Mn trigonal bipyramids that share  a cornercorner with one Se(1)La3Al tetrahedra,  a cornercorner with one Se(2)La3Al tetrahedra,  a cornercorner with one Se(3)La3Al tetrahedra,  a cornercorner with one Se(4)La3Al tetrahedra,  an edgeedge with one Se(17)La4Mn trigonal bipyramid, and  an edgeedge with one Se(20)La4Mn trigonal bipyramid. In the twenty-third Se site, Se(23) is bonded in a 5-coordinate geometry to one La(12), one La(3), one La(4), one La(8), and one Mn(1) atom. In the twenty-fourth Se site, Se(24) is bonded in a 6-coordinate geometry to one La(11), one La(3), one La(4), one La(7), one Mn(2), and one Mn(3) atom. In the twenty-fifth Se site, Se(25) is bonded in a 6-coordinate geometry to one La(10), one La(5), one La(6), one La(7), one Mn(2), and one Mn(3) atom. In the twenty-sixth Se site, Se(26) is bonded in a 5-coordinate geometry to one La(5), one La(6), one La(8), one La(9), and one Mn(1) atom. In the twenty-seventh Se site, Se(27) is bonded in a 6-coordinate geometry to one La(1), one La(10), one La(11), one La(2), one Mn(2), and one Mn(3) atom. In the twenty-eighth Se site, Se(28) is bonded in a 5-coordinate geometry to one La(1), one La(12), one La(2), one La(9), and one Mn(1) atom.
La12Mn3(AlSe7)4 crystallizes in the triclinic P1 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(13), one Se(15), one Se(18), one Se(19), one Se(27), one Se(28), one Se(4), and one Se(7) atom. The La(1)-Se(13) bond length is 3.02 Å. The La(1)-Se(15) bond length is 3.11 Å. The La(1)-Se(18) bond length is 3.08 Å. The La(1)-Se(19) bond length is 3.07 Å. The La(1)-Se(27) bond length is 3.58 Å. The La(1)-Se(28) bond length is 3.13 Å. The La(1)-Se(4) bond length is 3.06 Å. The La(1)-Se(7) bond length is 3.14 Å. In the second La site, La(2) is bonded in a 8-coordinate geometry to one Se(14), one Se(16), one Se(17), one Se(20), one Se(27), one Se(28), one Se(3), and one Se(8) atom. The La(2)-Se(14) bond length is 3.02 Å. The La(2)-Se(16) bond length is 3.10 Å. The La(2)-Se(17) bond length is 3.02 Å. The La(2)-Se(20) bond length is 3.06 Å. The La(2)-Se(27) bond length is 3.28 Å. The La(2)-Se(28) bond length is 3.59 Å. The La(2)-Se(3) bond length is 3.09 Å. The La(2)-Se(8) bond length is 3.14 Å. In the third La site, La(3) is bonded in a 8-coordinate geometry to one Se(10), one Se(11), one Se(15), one Se(20), one Se(22), one Se(23), one Se(24), and one Se(4) atom. The La(3)-Se(10) bond length is 3.15 Å. The La(3)-Se(11) bond length is 3.11 Å. The La(3)-Se(15) bond length is 3.02 Å. The La(3)-Se(20) bond length is 3.02 Å. The La(3)-Se(22) bond length is 3.04 Å. The La(3)-Se(23) bond length is 3.58 Å. The La(3)-Se(24) bond length is 3.30 Å. The La(3)-Se(4) bond length is 3.08 Å. In the fourth La site, La(4) is bonded in a 8-coordinate geometry to one Se(12), one Se(16), one Se(19), one Se(21), one Se(23), one Se(24), one Se(3), and one Se(9) atom. The La(4)-Se(12) bond length is 3.10 Å. The La(4)-Se(16) bond length is 3.02 Å. The La(4)-Se(19) bond length is 3.08 Å. The La(4)-Se(21) bond length is 3.08 Å. The La(4)-Se(23) bond length is 3.13 Å. The La(4)-Se(24) bond length is 3.57 Å. The La(4)-Se(3) bond length is 3.07 Å. The La(4)-Se(9) bond length is 3.13 Å. In the fifth La site, La(5) is bonded in a 8-coordinate geometry to one Se(11), one Se(13), one Se(18), one Se(21), one Se(25), one Se(26), one Se(4), and one Se(6) atom. The La(5)-Se(11) bond length is 3.02 Å. The La(5)-Se(13) bond length is 3.10 Å. The La(5)-Se(18) bond length is 3.06 Å. The La(5)-Se(21) bond length is 3.07 Å. The La(5)-Se(25) bond length is 3.59 Å. The La(5)-Se(26) bond length is 3.13 Å. The La(5)-Se(4) bond length is 3.06 Å. The La(5)-Se(6) bond length is 3.12 Å. In the sixth La site, La(6) is bonded in a 8-coordinate geometry to one Se(12), one Se(14), one Se(17), one Se(22), one Se(25), one Se(26), one Se(3), and one Se(5) atom. The La(6)-Se(12) bond length is 3.02 Å. The La(6)-Se(14) bond length is 3.12 Å. The La(6)-Se(17) bond length is 3.04 Å. The La(6)-Se(22) bond length is 3.02 Å. The La(6)-Se(25) bond length is 3.28 Å. The La(6)-Se(26) bond length is 3.58 Å. The La(6)-Se(3) bond length is 3.09 Å. The La(6)-Se(5) bond length is 3.17 Å. In the seventh La site, La(7) is bonded in a 8-coordinate geometry to one Se(10), one Se(13), one Se(2), one Se(21), one Se(22), one Se(24), one Se(25), and one Se(8) atom. The La(7)-Se(10) bond length is 3.10 Å. The La(7)-Se(13) bond length is 3.16 Å. The La(7)-Se(2) bond length is 3.09 Å. The La(7)-Se(21) bond length is 3.30 Å. The La(7)-Se(22) bond length is 3.32 Å. The La(7)-Se(24) bond length is 3.06 Å. The La(7)-Se(25) bond length is 3.06 Å. The La(7)-Se(8) bond length is 2.98 Å. In the eighth La site, La(8) is bonded in a 8-coordinate geometry to one Se(1), one Se(14), one Se(21), one Se(22), one Se(23), one Se(26), one Se(7), and one Se(9) atom. The La(8)-Se(1) bond length is 3.09 Å. The La(8)-Se(14) bond length is 3.14 Å. The La(8)-Se(21) bond length is 3.58 Å. The La(8)-Se(22) bond length is 3.37 Å. The La(8)-Se(23) bond length is 3.06 Å. The La(8)-Se(26) bond length is 3.01 Å. The La(8)-Se(7) bond length is 3.03 Å. The La(8)-Se(9) bond length is 3.09 Å. In the ninth La site, La(9) is bonded in a 8-coordinate geometry to one Se(10), one Se(16), one Se(17), one Se(18), one Se(2), one Se(26), one Se(28), and one Se(6) atom. The La(9)-Se(10) bond length is 3.03 Å. The La(9)-Se(16) bond length is 3.14 Å. The La(9)-Se(17) bond length is 3.34 Å. The La(9)-Se(18) bond length is 3.60 Å. The La(9)-Se(2) bond length is 3.08 Å. The La(9)-Se(26) bond length is 3.06 Å. The La(9)-Se(28) bond length is 3.01 Å. The La(9)-Se(6) bond length is 3.09 Å. In the tenth La site, La(10) is bonded in a 8-coordinate geometry to one Se(1), one Se(15), one Se(17), one Se(18), one Se(25), one Se(27), one Se(5), and one Se(9) atom. The La(10)-Se(1) bond length is 3.09 Å. The La(10)-Se(15) bond length is 3.15 Å. The La(10)-Se(17) bond length is 3.32 Å. The La(10)-Se(18) bond length is 3.30 Å. The La(10)-Se(25) bond length is 3.07 Å. The La(10)-Se(27) bond length is 3.06 Å. The La(10)-Se(5) bond length is 3.11 Å. The La(10)-Se(9) bond length is 2.98 Å. In the eleventh La site, La(11) is bonded in a 8-coordinate geometry to one Se(12), one Se(19), one Se(2), one Se(20), one Se(24), one Se(27), one Se(6), and one Se(8) atom. The La(11)-Se(12) bond length is 3.15 Å. The La(11)-Se(19) bond length is 3.31 Å. The La(11)-Se(2) bond length is 3.09 Å. The La(11)-Se(20) bond length is 3.32 Å. The La(11)-Se(24) bond length is 3.05 Å. The La(11)-Se(27) bond length is 3.08 Å. The La(11)-Se(6) bond length is 2.99 Å. The La(11)-Se(8) bond length is 3.08 Å. In the twelfth La site, La(12) is bonded in a 8-coordinate geometry to one Se(1), one Se(11), one Se(19), one Se(20), one Se(23), one Se(28), one Se(5), and one Se(7) atom. The La(12)-Se(1) bond length is 3.09 Å. The La(12)-Se(11) bond length is 3.15 Å. The La(12)-Se(19) bond length is 3.58 Å. The La(12)-Se(20) bond length is 3.37 Å. The La(12)-Se(23) bond length is 3.02 Å. The La(12)-Se(28) bond length is 3.06 Å. The La(12)-Se(5) bond length is 3.02 Å. The La(12)-Se(7) bond length is 3.12 Å. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one Se(18), one Se(19), one Se(21), one Se(23), one Se(26), and one Se(28) atom to form face-sharing MnSe6 octahedra. The Mn(1)-Se(18) bond length is 2.81 Å. The Mn(1)-Se(19) bond length is 2.80 Å. The Mn(1)-Se(21) bond length is 2.80 Å. The Mn(1)-Se(23) bond length is 2.60 Å. The Mn(1)-Se(26) bond length is 2.60 Å. The Mn(1)-Se(28) bond length is 2.60 Å. In the second Mn site, Mn(2) is bonded to one Se(17), one Se(20), one Se(22), one Se(24), one Se(25), and one Se(27) atom to form face-sharing MnSe6 octahedra. The Mn(2)-Se(17) bond length is 2.61 Å. The Mn(2)-Se(20) bond length is 2.58 Å. The Mn(2)-Se(22) bond length is 2.59 Å. The Mn(2)-Se(24) bond length is 2.76 Å. The Mn(2)-Se(25) bond length is 2.73 Å. The Mn(2)-Se(27) bond length is 2.74 Å. In the third Mn site, Mn(3) is bonded to one Se(18), one Se(19), one Se(21), one Se(24), one Se(25), and one Se(27) atom to form face-sharing MnSe6 octahedra. The Mn(3)-Se(18) bond length is 2.64 Å. The Mn(3)-Se(19) bond length is 2.64 Å. The Mn(3)-Se(21) bond length is 2.65 Å. The Mn(3)-Se(24) bond length is 2.69 Å. The Mn(3)-Se(25) bond length is 2.69 Å. The Mn(3)-Se(27) bond length is 2.69 Å. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a tetrahedral geometry to one Se(2), one Se(5), one Se(7), and one Se(9) atom. The Al(1)-Se(2) bond length is 2.36 Å. The Al(1)-Se(5) bond length is 2.41 Å. The Al(1)-Se(7) bond length is 2.40 Å. The Al(1)-Se(9) bond length is 2.40 Å. In the second Al site, Al(2) is bonded in a tetrahedral geometry to one Se(1), one Se(10), one Se(6), and one Se(8) atom. The Al(2)-Se(1) bond length is 2.36 Å. The Al(2)-Se(10) bond length is 2.40 Å. The Al(2)-Se(6) bond length is 2.40 Å. The Al(2)-Se(8) bond length is 2.41 Å. In the third Al site, Al(3) is bonded in a tetrahedral geometry to one Se(11), one Se(13), one Se(15), and one Se(3) atom. The Al(3)-Se(11) bond length is 2.40 Å. The Al(3)-Se(13) bond length is 2.41 Å. The Al(3)-Se(15) bond length is 2.40 Å. The Al(3)-Se(3) bond length is 2.36 Å. In the fourth Al site, Al(4) is bonded in a tetrahedral geometry to one Se(12), one Se(14), one Se(16), and one Se(4) atom. The Al(4)-Se(12) bond length is 2.41 Å. The Al(4)-Se(14) bond length is 2.40 Å. The Al(4)-Se(16) bond length is 2.40 Å. The Al(4)-Se(4) bond length is 2.36 Å. There are twenty-eight inequivalent Se sites. In the first Se site, Se(1) is bonded to one La(10), one La(12), one La(8), and one Al(2) atom to form corner-sharing SeLa3Al tetrahedra. In the second Se site, Se(2) is bonded to one La(11), one La(7), one La(9), and one Al(1) atom to form corner-sharing SeLa3Al tetrahedra. In the third Se site, Se(3) is bonded to one La(2), one La(4), one La(6), and one Al(3) atom to form corner-sharing SeLa3Al tetrahedra. In the fourth Se site, Se(4) is bonded to one La(1), one La(3), one La(5), and one Al(4) atom to form corner-sharing SeLa3Al tetrahedra. In the fifth Se site, Se(5) is bonded in a distorted rectangular see-saw-like geometry to one La(10), one La(12), one La(6), and one Al(1) atom. In the sixth Se site, Se(6) is bonded in a rectangular see-saw-like geometry to one La(11), one La(5), one La(9), and one Al(2) atom. In the seventh Se site, Se(7) is bonded in a distorted rectangular see-saw-like geometry to one La(1), one La(12), one La(8), and one Al(1) atom. In the eighth Se site, Se(8) is bonded in a distorted rectangular see-saw-like geometry to one La(11), one La(2), one La(7), and one Al(2) atom. In the ninth Se site, Se(9) is bonded in a distorted rectangular see-saw-like geometry to one La(10), one La(4), one La(8), and one Al(1) atom. In the tenth Se site, Se(10) is bonded in a distorted rectangular see-saw-like geometry to one La(3), one La(7), one La(9), and one Al(2) atom. In the eleventh Se site, Se(11) is bonded in a distorted rectangular see-saw-like geometry to one La(12), one La(3), one La(5), and one Al(3) atom. In the twelfth Se site, Se(12) is bonded in a distorted rectangular see-saw-like geometry to one La(11), one La(4), one La(6), and one Al(4) atom. In the thirteenth Se site, Se(13) is bonded in a distorted rectangular see-saw-like geometry to one La(1), one La(5), one La(7), and one Al(3) atom. In the fourteenth Se site, Se(14) is bonded in a distorted rectangular see-saw-like geometry to one La(2), one La(6), one La(8), and one Al(4) atom. In the fifteenth Se site, Se(15) is bonded in a distorted rectangular see-saw-like geometry to one La(1), one La(10), one La(3), and one Al(3) atom. In the sixteenth Se site, Se(16) is bonded in a distorted rectangular see-saw-like geometry to one La(2), one La(4), one La(9), and one Al(4) atom. In the seventeenth Se site, Se(17) is bonded to one La(10), one La(2), one La(6), one La(9), and one Mn(2) atom to form distorted SeLa4Mn trigonal bipyramids that share  a cornercorner with one Se(1)La3Al tetrahedra,  a cornercorner with one Se(2)La3Al tetrahedra, corners with two equivalent Se(3)La3Al tetrahedra,  an edgeedge with one Se(20)La4Mn trigonal bipyramid, and  an edgeedge with one Se(22)La4Mn trigonal bipyramid. In the eighteenth Se site, Se(18) is bonded in a 6-coordinate geometry to one La(1), one La(10), one La(5), one La(9), one Mn(1), and one Mn(3) atom. In the nineteenth Se site, Se(19) is bonded in a 6-coordinate geometry to one La(1), one La(11), one La(12), one La(4), one Mn(1), and one Mn(3) atom. In the twentieth Se site, Se(20) is bonded to one La(11), one La(12), one La(2), one La(3), and one Mn(2) atom to form distorted SeLa4Mn trigonal bipyramids that share  a cornercorner with one Se(1)La3Al tetrahedra,  a cornercorner with one Se(2)La3Al tetrahedra,  a cornercorner with one Se(3)La3Al tetrahedra,  a cornercorner with one Se(4)La3Al tetrahedra,  an edgeedge with one Se(17)La4Mn trigonal bipyramid, and  an edgeedge with one Se(22)La4Mn trigonal bipyramid. In the twenty-first Se site, Se(21) is bonded in a 6-coordinate geometry to one La(4), one La(5), one La(7), one La(8), one Mn(1), and one Mn(3) atom. In the twenty-second Se site, Se(22) is bonded to one La(3), one La(6), one La(7), one La(8), and one Mn(2) atom to form distorted SeLa4Mn trigonal bipyramids that share  a cornercorner with one Se(1)La3Al tetrahedra,  a cornercorner with one Se(2)La3Al tetrahedra,  a cornercorner with one Se(3)La3Al tetrahedra,  a cornercorner with one Se(4)La3Al tetrahedra,  an edgeedge with one Se(17)La4Mn trigonal bipyramid, and  an edgeedge with one Se(20)La4Mn trigonal bipyramid. In the twenty-third Se site, Se(23) is bonded in a 5-coordinate geometry to one La(12), one La(3), one La(4), one La(8), and one Mn(1) atom. In the twenty-fourth Se site, Se(24) is bonded in a 6-coordinate geometry to one La(11), one La(3), one La(4), one La(7), one Mn(2), and one Mn(3) atom. In the twenty-fifth Se site, Se(25) is bonded in a 6-coordinate geometry to one La(10), one La(5), one La(6), one La(7), one Mn(2), and one Mn(3) atom. In the twenty-sixth Se site, Se(26) is bonded in a 5-coordinate geometry to one La(5), one La(6), one La(8), one La(9), and one Mn(1) atom. In the twenty-seventh Se site, Se(27) is bonded in a 6-coordinate geometry to one La(1), one La(10), one La(11), one La(2), one Mn(2), and one Mn(3) atom. In the twenty-eighth Se site, Se(28) is bonded in a 5-coordinate geometry to one La(1), one La(12), one La(2), one La(9), and one Mn(1) atom.