La2Nb2N2O5 crystallizes in the triclinic P1 space group. There are eight inequivalent La sites. In the first La site, La(1) is bonded in a 7-coordinate geometry to one N(1), one N(4), one N(8), one O(1), one O(11), one O(4), and one O(7) atom. In the second La site, La(2) is bonded in a 9-coordinate geometry to one N(1), one N(3), one N(7), one O(12), one O(15), one O(3), one O(5), one O(8), and one O(9) atom. In the third La site, La(3) is bonded in a 9-coordinate geometry to one O(10), one O(14), one O(15), one O(18), one O(2), one O(3), one O(5), one O(6), and one O(9) atom. In the fourth La site, La(4) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(14), one O(16), one O(19), one O(4), and one O(6) atom. In the fifth La site, La(5) is bonded in a 8-coordinate geometry to one N(4), one N(8), one O(11), one O(13), one O(16), one O(17), one O(20), and one O(7) atom. In the sixth La site, La(6) is bonded in a 8-coordinate geometry to one N(2), one N(3), one N(7), one O(12), one O(13), one O(17), one O(20), and one O(8) atom. In the seventh La site, La(7) is bonded in a 10-coordinate geometry to one N(2), one N(3), one N(6), two equivalent N(5), one O(12), one O(15), one O(18), one O(2), and one O(5) atom. In the eighth La site, La(8) is bonded in a 7-coordinate geometry to one N(4), one N(6), one N(8), one O(1), one O(16), one O(19), and one O(4) atom. There are eight inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one N(6), one O(1), one O(10), one O(2), one O(4), and one O(6) atom to form NbNO5 octahedra that share corners with two equivalent Nb(2)N2O4 octahedra and corners with two equivalent Nb(6)NO5 octahedra. The corner-sharing octahedral tilt angles range from 22-37°. In the second Nb site, Nb(2) is bonded to one N(3), one N(5), one O(2), one O(5), one O(6), and one O(9) atom to form NbN2O4 octahedra that share corners with two equivalent Nb(7)N3O3 octahedra, corners with two equivalent Nb(1)NO5 octahedra, and corners with two equivalent Nb(5)NO5 octahedra. The corner-sharing octahedral tilt angles range from 17-37°. In the third Nb site, Nb(3) is bonded to one N(1), one O(11), one O(13), one O(17), one O(7), and one O(8) atom to form distorted NbNO5 octahedra that share corners with two equivalent Nb(8)N4O2 octahedra and corners with two equivalent Nb(4)NO5 octahedra. The corner-sharing octahedral tilt angles range from 26-43°. In the fourth Nb site, Nb(4) is bonded to one N(2), one O(12), one O(13), one O(15), one O(3), and one O(8) atom to form distorted NbNO5 octahedra that share corners with two equivalent Nb(7)N3O3 octahedra, corners with two equivalent Nb(3)NO5 octahedra, and corners with two equivalent Nb(5)NO5 octahedra. The corner-sharing octahedral tilt angles range from 17-43°. In the fifth Nb site, Nb(5) is bonded to one N(5), one O(12), one O(14), one O(15), one O(18), and one O(9) atom to form distorted NbNO5 octahedra that share corners with two equivalent Nb(2)N2O4 octahedra, corners with two equivalent Nb(4)NO5 octahedra, and corners with two equivalent Nb(6)NO5 octahedra. The corner-sharing octahedral tilt angles range from 17-42°. In the sixth Nb site, Nb(6) is bonded to one N(6), one O(10), one O(14), one O(16), one O(18), and one O(19) atom to form distorted corner-sharing NbNO5 octahedra. The corner-sharing octahedral tilt angles range from 26-42°. In the seventh Nb site, Nb(7) is bonded to one N(2), one N(3), one N(7), one O(20), one O(3), and one O(5) atom to form distorted NbN3O3 octahedra that share corners with two equivalent Nb(2)N2O4 octahedra, corners with two equivalent Nb(8)N4O2 octahedra, and corners with two equivalent Nb(4)NO5 octahedra. The corner-sharing octahedral tilt angles range from 17-45°. In the eighth Nb site, Nb(8) is bonded to one N(1), one N(4), one N(7), one N(8), one O(17), and one O(20) atom to form distorted NbN4O2 octahedra that share corners with two equivalent Nb(7)N3O3 octahedra and corners with two equivalent Nb(3)NO5 octahedra. The corner-sharing octahedral tilt angles range from 26-45°. There are eight inequivalent N sites. In the first N site, N(1) is bonded in a 4-coordinate geometry to one La(1), one La(2), one Nb(3), and one Nb(8) atom. In the second N site, N(2) is bonded in a 4-coordinate geometry to one La(6), one La(7), one Nb(4), and one Nb(7) atom. In the third N site, N(3) is bonded in a 5-coordinate geometry to one La(2), one La(6), one La(7), one Nb(2), and one Nb(7) atom. In the fourth N site, N(4) is bonded to one La(1), one La(5), one La(8), and one Nb(8) atom to form NLa3Nb tetrahedra that share  a cornercorner with one N(7)La2Nb2 tetrahedra, corners with two equivalent O(16)La3Nb tetrahedra, corners with two equivalent O(4)La3Nb tetrahedra,  an edgeedge with one O(1)La3Nb tetrahedra, and edges with two equivalent N(8)La3Nb tetrahedra. In the fifth N site, N(5) is bonded in a 3-coordinate geometry to two equivalent La(7), one Nb(2), and one Nb(5) atom. In the sixth N site, N(6) is bonded in a 2-coordinate geometry to one La(7), one La(8), one Nb(1), and one Nb(6) atom. In the seventh N site, N(7) is bonded to one La(2), one La(6), one Nb(7), and one Nb(8) atom to form distorted NLa2Nb2 tetrahedra that share  a cornercorner with one N(4)La3Nb tetrahedra,  a cornercorner with one N(8)La3Nb tetrahedra,  a cornercorner with one O(9)La2Nb2 tetrahedra, and corners with two equivalent O(8)La2Nb2 tetrahedra. In the eighth N site, N(8) is bonded to one La(1), one La(5), one La(8), and one Nb(8) atom to form NLa3Nb tetrahedra that share  a cornercorner with one N(7)La2Nb2 tetrahedra, corners with two equivalent O(1)La3Nb tetrahedra,  an edgeedge with one O(16)La3Nb tetrahedra,  an edgeedge with one O(4)La3Nb tetrahedra, and edges with two equivalent N(4)La3Nb tetrahedra. There are twenty inequivalent O sites. In the first O site, O(1) is bonded to one La(1), one La(4), one La(8), and one Nb(1) atom to form OLa3Nb tetrahedra that share corners with two equivalent N(8)La3Nb tetrahedra, corners with two equivalent O(16)La3Nb tetrahedra,  an edgeedge with one N(4)La3Nb tetrahedra, and edges with two equivalent O(4)La3Nb tetrahedra. In the second O site, O(2) is bonded in a distorted see-saw-like geometry to one La(3), one La(7), one Nb(1), and one Nb(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one La(2), one La(3), one Nb(4), and one Nb(7) atom. In the fourth O site, O(4) is bonded to one La(1), one La(4), one La(8), and one Nb(1) atom to form distorted OLa3Nb tetrahedra that share corners with two equivalent N(4)La3Nb tetrahedra, corners with two equivalent O(16)La3Nb tetrahedra,  an edgeedge with one N(8)La3Nb tetrahedra, and edges with two equivalent O(1)La3Nb tetrahedra. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one La(2), one La(3), one La(7), one Nb(2), and one Nb(7) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one La(3), one La(4), one Nb(1), and one Nb(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one La(1), one La(5), and one Nb(3) atom. In the eighth O site, O(8) is bonded to one La(2), one La(6), one Nb(3), and one Nb(4) atom to form distorted OLa2Nb2 tetrahedra that share  a cornercorner with one O(9)La2Nb2 tetrahedra and corners with two equivalent N(7)La2Nb2 tetrahedra. In the ninth O site, O(9) is bonded to one La(2), one La(3), one Nb(2), and one Nb(5) atom to form distorted OLa2Nb2 tetrahedra that share  a cornercorner with one N(7)La2Nb2 tetrahedra,  a cornercorner with one O(8)La2Nb2 tetrahedra, and  an edgeedge with one O(18)La2Nb2 tetrahedra. In the tenth O site, O(10) is bonded in a distorted see-saw-like geometry to one La(3), one La(4), one Nb(1), and one Nb(6) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one La(1), one La(4), one La(5), and one Nb(3) atom. In the twelfth O site, O(12) is bonded in a 5-coordinate geometry to one La(2), one La(6), one La(7), one Nb(4), and one Nb(5) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one La(5), one La(6), one Nb(3), and one Nb(4) atom. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one La(3), one La(4), one Nb(5), and one Nb(6) atom. In the fifteenth O site, O(15) is bonded in a 5-coordinate geometry to one La(2), one La(3), one La(7), one Nb(4), and one Nb(5) atom. In the sixteenth O site, O(16) is bonded to one La(4), one La(5), one La(8), and one Nb(6) atom to form distorted OLa3Nb tetrahedra that share  a cornercorner with one O(18)La2Nb2 tetrahedra, corners with two equivalent N(4)La3Nb tetrahedra, corners with two equivalent O(1)La3Nb tetrahedra, corners with two equivalent O(4)La3Nb tetrahedra, and  an edgeedge with one N(8)La3Nb tetrahedra. In the seventeenth O site, O(17) is bonded in a distorted see-saw-like geometry to one La(5), one La(6), one Nb(3), and one Nb(8) atom. In the eighteenth O site, O(18) is bonded to one La(3), one La(7), one Nb(5), and one Nb(6) atom to form distorted OLa2Nb2 tetrahedra that share  a cornercorner with one O(16)La3Nb tetrahedra and  an edgeedge with one O(9)La2Nb2 tetrahedra. In the nineteenth O site, O(19) is bonded in a distorted trigonal planar geometry to one La(4), one La(8), and one Nb(6) atom. In the twentieth O site, O(20) is bonded in a 4-coordinate geometry to one La(5), one La(6), one Nb(7), and one Nb(8) atom.
La2Nb2N2O5 crystallizes in the triclinic P1 space group. There are eight inequivalent La sites. In the first La site, La(1) is bonded in a 7-coordinate geometry to one N(1), one N(4), one N(8), one O(1), one O(11), one O(4), and one O(7) atom. The La(1)-N(1) bond length is 2.63 Å. The La(1)-N(4) bond length is 2.46 Å. The La(1)-N(8) bond length is 2.48 Å. The La(1)-O(1) bond length is 2.52 Å. The La(1)-O(11) bond length is 2.64 Å. The La(1)-O(4) bond length is 2.55 Å. The La(1)-O(7) bond length is 2.46 Å. In the second La site, La(2) is bonded in a 9-coordinate geometry to one N(1), one N(3), one N(7), one O(12), one O(15), one O(3), one O(5), one O(8), and one O(9) atom. The La(2)-N(1) bond length is 2.81 Å. The La(2)-N(3) bond length is 2.82 Å. The La(2)-N(7) bond length is 2.41 Å. The La(2)-O(12) bond length is 2.82 Å. The La(2)-O(15) bond length is 2.83 Å. The La(2)-O(3) bond length is 2.45 Å. The La(2)-O(5) bond length is 2.90 Å. The La(2)-O(8) bond length is 2.43 Å. The La(2)-O(9) bond length is 2.58 Å. In the third La site, La(3) is bonded in a 9-coordinate geometry to one O(10), one O(14), one O(15), one O(18), one O(2), one O(3), one O(5), one O(6), and one O(9) atom. The La(3)-O(10) bond length is 2.55 Å. The La(3)-O(14) bond length is 2.71 Å. The La(3)-O(15) bond length is 2.49 Å. The La(3)-O(18) bond length is 2.55 Å. The La(3)-O(2) bond length is 2.58 Å. The La(3)-O(3) bond length is 3.06 Å. The La(3)-O(5) bond length is 2.44 Å. The La(3)-O(6) bond length is 2.60 Å. The La(3)-O(9) bond length is 2.44 Å. In the fourth La site, La(4) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(14), one O(16), one O(19), one O(4), and one O(6) atom. The La(4)-O(1) bond length is 2.46 Å. The La(4)-O(10) bond length is 2.56 Å. The La(4)-O(11) bond length is 2.56 Å. The La(4)-O(14) bond length is 2.90 Å. The La(4)-O(16) bond length is 2.67 Å. The La(4)-O(19) bond length is 2.44 Å. The La(4)-O(4) bond length is 2.49 Å. The La(4)-O(6) bond length is 2.90 Å. In the fifth La site, La(5) is bonded in a 8-coordinate geometry to one N(4), one N(8), one O(11), one O(13), one O(16), one O(17), one O(20), and one O(7) atom. The La(5)-N(4) bond length is 2.46 Å. The La(5)-N(8) bond length is 2.46 Å. The La(5)-O(11) bond length is 2.73 Å. The La(5)-O(13) bond length is 2.88 Å. The La(5)-O(16) bond length is 2.70 Å. The La(5)-O(17) bond length is 2.71 Å. The La(5)-O(20) bond length is 2.76 Å. The La(5)-O(7) bond length is 2.58 Å. In the sixth La site, La(6) is bonded in a 8-coordinate geometry to one N(2), one N(3), one N(7), one O(12), one O(13), one O(17), one O(20), and one O(8) atom. The La(6)-N(2) bond length is 2.51 Å. The La(6)-N(3) bond length is 2.59 Å. The La(6)-N(7) bond length is 2.51 Å. The La(6)-O(12) bond length is 2.61 Å. The La(6)-O(13) bond length is 2.67 Å. The La(6)-O(17) bond length is 2.46 Å. The La(6)-O(20) bond length is 2.61 Å. The La(6)-O(8) bond length is 2.58 Å. In the seventh La site, La(7) is bonded in a 10-coordinate geometry to one N(2), one N(3), one N(6), two equivalent N(5), one O(12), one O(15), one O(18), one O(2), and one O(5) atom. The La(7)-N(2) bond length is 2.50 Å. The La(7)-N(3) bond length is 2.74 Å. The La(7)-N(6) bond length is 2.91 Å. There is one shorter (2.57 Å) and one longer (3.16 Å) La(7)-N(5) bond length. The La(7)-O(12) bond length is 2.77 Å. The La(7)-O(15) bond length is 2.91 Å. The La(7)-O(18) bond length is 2.42 Å. The La(7)-O(2) bond length is 2.48 Å. The La(7)-O(5) bond length is 2.79 Å. In the eighth La site, La(8) is bonded in a 7-coordinate geometry to one N(4), one N(6), one N(8), one O(1), one O(16), one O(19), and one O(4) atom. The La(8)-N(4) bond length is 2.43 Å. The La(8)-N(6) bond length is 2.76 Å. The La(8)-N(8) bond length is 2.45 Å. The La(8)-O(1) bond length is 2.54 Å. The La(8)-O(16) bond length is 2.64 Å. The La(8)-O(19) bond length is 2.42 Å. The La(8)-O(4) bond length is 2.58 Å. There are eight inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one N(6), one O(1), one O(10), one O(2), one O(4), and one O(6) atom to form NbNO5 octahedra that share corners with two equivalent Nb(2)N2O4 octahedra and corners with two equivalent Nb(6)NO5 octahedra. The corner-sharing octahedral tilt angles range from 22-37°. The Nb(1)-N(6) bond length is 1.93 Å. The Nb(1)-O(1) bond length is 2.04 Å. The Nb(1)-O(10) bond length is 2.28 Å. The Nb(1)-O(2) bond length is 2.09 Å. The Nb(1)-O(4) bond length is 1.96 Å. The Nb(1)-O(6) bond length is 2.05 Å. In the second Nb site, Nb(2) is bonded to one N(3), one N(5), one O(2), one O(5), one O(6), and one O(9) atom to form NbN2O4 octahedra that share corners with two equivalent Nb(7)N3O3 octahedra, corners with two equivalent Nb(1)NO5 octahedra, and corners with two equivalent Nb(5)NO5 octahedra. The corner-sharing octahedral tilt angles range from 17-37°. The Nb(2)-N(3) bond length is 1.92 Å. The Nb(2)-N(5) bond length is 2.03 Å. The Nb(2)-O(2) bond length is 2.06 Å. The Nb(2)-O(5) bond length is 2.03 Å. The Nb(2)-O(6) bond length is 2.26 Å. The Nb(2)-O(9) bond length is 2.17 Å. In the third Nb site, Nb(3) is bonded to one N(1), one O(11), one O(13), one O(17), one O(7), and one O(8) atom to form distorted NbNO5 octahedra that share corners with two equivalent Nb(8)N4O2 octahedra and corners with two equivalent Nb(4)NO5 octahedra. The corner-sharing octahedral tilt angles range from 26-43°. The Nb(3)-N(1) bond length is 1.93 Å. The Nb(3)-O(11) bond length is 1.96 Å. The Nb(3)-O(13) bond length is 2.39 Å. The Nb(3)-O(17) bond length is 2.19 Å. The Nb(3)-O(7) bond length is 1.88 Å. The Nb(3)-O(8) bond length is 2.21 Å. In the fourth Nb site, Nb(4) is bonded to one N(2), one O(12), one O(13), one O(15), one O(3), and one O(8) atom to form distorted NbNO5 octahedra that share corners with two equivalent Nb(7)N3O3 octahedra, corners with two equivalent Nb(3)NO5 octahedra, and corners with two equivalent Nb(5)NO5 octahedra. The corner-sharing octahedral tilt angles range from 17-43°. The Nb(4)-N(2) bond length is 1.94 Å. The Nb(4)-O(12) bond length is 2.07 Å. The Nb(4)-O(13) bond length is 1.92 Å. The Nb(4)-O(15) bond length is 2.36 Å. The Nb(4)-O(3) bond length is 2.19 Å. The Nb(4)-O(8) bond length is 2.00 Å. In the fifth Nb site, Nb(5) is bonded to one N(5), one O(12), one O(14), one O(15), one O(18), and one O(9) atom to form distorted NbNO5 octahedra that share corners with two equivalent Nb(2)N2O4 octahedra, corners with two equivalent Nb(4)NO5 octahedra, and corners with two equivalent Nb(6)NO5 octahedra. The corner-sharing octahedral tilt angles range from 17-42°. The Nb(5)-N(5) bond length is 1.96 Å. The Nb(5)-O(12) bond length is 2.29 Å. The Nb(5)-O(14) bond length is 1.94 Å. The Nb(5)-O(15) bond length is 2.03 Å. The Nb(5)-O(18) bond length is 2.04 Å. The Nb(5)-O(9) bond length is 2.13 Å. In the sixth Nb site, Nb(6) is bonded to one N(6), one O(10), one O(14), one O(16), one O(18), and one O(19) atom to form distorted corner-sharing NbNO5 octahedra. The corner-sharing octahedral tilt angles range from 26-42°. The Nb(6)-N(6) bond length is 2.03 Å. The Nb(6)-O(10) bond length is 2.08 Å. The Nb(6)-O(14) bond length is 2.27 Å. The Nb(6)-O(16) bond length is 1.92 Å. The Nb(6)-O(18) bond length is 2.20 Å. The Nb(6)-O(19) bond length is 1.89 Å. In the seventh Nb site, Nb(7) is bonded to one N(2), one N(3), one N(7), one O(20), one O(3), and one O(5) atom to form distorted NbN3O3 octahedra that share corners with two equivalent Nb(2)N2O4 octahedra, corners with two equivalent Nb(8)N4O2 octahedra, and corners with two equivalent Nb(4)NO5 octahedra. The corner-sharing octahedral tilt angles range from 17-45°. The Nb(7)-N(2) bond length is 2.11 Å. The Nb(7)-N(3) bond length is 2.28 Å. The Nb(7)-N(7) bond length is 1.90 Å. The Nb(7)-O(20) bond length is 1.91 Å. The Nb(7)-O(3) bond length is 2.10 Å. The Nb(7)-O(5) bond length is 2.32 Å. In the eighth Nb site, Nb(8) is bonded to one N(1), one N(4), one N(7), one N(8), one O(17), and one O(20) atom to form distorted NbN4O2 octahedra that share corners with two equivalent Nb(7)N3O3 octahedra and corners with two equivalent Nb(3)NO5 octahedra. The corner-sharing octahedral tilt angles range from 26-45°. The Nb(8)-N(1) bond length is 2.11 Å. The Nb(8)-N(4) bond length is 1.93 Å. The Nb(8)-N(7) bond length is 2.22 Å. The Nb(8)-N(8) bond length is 1.90 Å. The Nb(8)-O(17) bond length is 2.16 Å. The Nb(8)-O(20) bond length is 2.48 Å. There are eight inequivalent N sites. In the first N site, N(1) is bonded in a 4-coordinate geometry to one La(1), one La(2), one Nb(3), and one Nb(8) atom. In the second N site, N(2) is bonded in a 4-coordinate geometry to one La(6), one La(7), one Nb(4), and one Nb(7) atom. In the third N site, N(3) is bonded in a 5-coordinate geometry to one La(2), one La(6), one La(7), one Nb(2), and one Nb(7) atom. In the fourth N site, N(4) is bonded to one La(1), one La(5), one La(8), and one Nb(8) atom to form NLa3Nb tetrahedra that share  a cornercorner with one N(7)La2Nb2 tetrahedra, corners with two equivalent O(16)La3Nb tetrahedra, corners with two equivalent O(4)La3Nb tetrahedra,  an edgeedge with one O(1)La3Nb tetrahedra, and edges with two equivalent N(8)La3Nb tetrahedra. In the fifth N site, N(5) is bonded in a 3-coordinate geometry to two equivalent La(7), one Nb(2), and one Nb(5) atom. In the sixth N site, N(6) is bonded in a 2-coordinate geometry to one La(7), one La(8), one Nb(1), and one Nb(6) atom. In the seventh N site, N(7) is bonded to one La(2), one La(6), one Nb(7), and one Nb(8) atom to form distorted NLa2Nb2 tetrahedra that share  a cornercorner with one N(4)La3Nb tetrahedra,  a cornercorner with one N(8)La3Nb tetrahedra,  a cornercorner with one O(9)La2Nb2 tetrahedra, and corners with two equivalent O(8)La2Nb2 tetrahedra. In the eighth N site, N(8) is bonded to one La(1), one La(5), one La(8), and one Nb(8) atom to form NLa3Nb tetrahedra that share  a cornercorner with one N(7)La2Nb2 tetrahedra, corners with two equivalent O(1)La3Nb tetrahedra,  an edgeedge with one O(16)La3Nb tetrahedra,  an edgeedge with one O(4)La3Nb tetrahedra, and edges with two equivalent N(4)La3Nb tetrahedra. There are twenty inequivalent O sites. In the first O site, O(1) is bonded to one La(1), one La(4), one La(8), and one Nb(1) atom to form OLa3Nb tetrahedra that share corners with two equivalent N(8)La3Nb tetrahedra, corners with two equivalent O(16)La3Nb tetrahedra,  an edgeedge with one N(4)La3Nb tetrahedra, and edges with two equivalent O(4)La3Nb tetrahedra. In the second O site, O(2) is bonded in a distorted see-saw-like geometry to one La(3), one La(7), one Nb(1), and one Nb(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one La(2), one La(3), one Nb(4), and one Nb(7) atom. In the fourth O site, O(4) is bonded to one La(1), one La(4), one La(8), and one Nb(1) atom to form distorted OLa3Nb tetrahedra that share corners with two equivalent N(4)La3Nb tetrahedra, corners with two equivalent O(16)La3Nb tetrahedra,  an edgeedge with one N(8)La3Nb tetrahedra, and edges with two equivalent O(1)La3Nb tetrahedra. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one La(2), one La(3), one La(7), one Nb(2), and one Nb(7) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one La(3), one La(4), one Nb(1), and one Nb(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one La(1), one La(5), and one Nb(3) atom. In the eighth O site, O(8) is bonded to one La(2), one La(6), one Nb(3), and one Nb(4) atom to form distorted OLa2Nb2 tetrahedra that share  a cornercorner with one O(9)La2Nb2 tetrahedra and corners with two equivalent N(7)La2Nb2 tetrahedra. In the ninth O site, O(9) is bonded to one La(2), one La(3), one Nb(2), and one Nb(5) atom to form distorted OLa2Nb2 tetrahedra that share  a cornercorner with one N(7)La2Nb2 tetrahedra,  a cornercorner with one O(8)La2Nb2 tetrahedra, and  an edgeedge with one O(18)La2Nb2 tetrahedra. In the tenth O site, O(10) is bonded in a distorted see-saw-like geometry to one La(3), one La(4), one Nb(1), and one Nb(6) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one La(1), one La(4), one La(5), and one Nb(3) atom. In the twelfth O site, O(12) is bonded in a 5-coordinate geometry to one La(2), one La(6), one La(7), one Nb(4), and one Nb(5) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one La(5), one La(6), one Nb(3), and one Nb(4) atom. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one La(3), one La(4), one Nb(5), and one Nb(6) atom. In the fifteenth O site, O(15) is bonded in a 5-coordinate geometry to one La(2), one La(3), one La(7), one Nb(4), and one Nb(5) atom. In the sixteenth O site, O(16) is bonded to one La(4), one La(5), one La(8), and one Nb(6) atom to form distorted OLa3Nb tetrahedra that share  a cornercorner with one O(18)La2Nb2 tetrahedra, corners with two equivalent N(4)La3Nb tetrahedra, corners with two equivalent O(1)La3Nb tetrahedra, corners with two equivalent O(4)La3Nb tetrahedra, and  an edgeedge with one N(8)La3Nb tetrahedra. In the seventeenth O site, O(17) is bonded in a distorted see-saw-like geometry to one La(5), one La(6), one Nb(3), and one Nb(8) atom. In the eighteenth O site, O(18) is bonded to one La(3), one La(7), one Nb(5), and one Nb(6) atom to form distorted OLa2Nb2 tetrahedra that share  a cornercorner with one O(16)La3Nb tetrahedra and  an edgeedge with one O(9)La2Nb2 tetrahedra. In the nineteenth O site, O(19) is bonded in a distorted trigonal planar geometry to one La(4), one La(8), and one Nb(6) atom. In the twentieth O site, O(20) is bonded in a 4-coordinate geometry to one La(5), one La(6), one Nb(7), and one Nb(8) atom.