La2Nb2N2O5 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 9-coordinate geometry to one N(2), two equivalent O(4), three equivalent O(3), and three equivalent O(5) atoms. In the second La site, La(2) is bonded in a 7-coordinate geometry to one N(2), three equivalent N(1), two equivalent O(1), and two equivalent O(2) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent N(1), one O(2), one O(4), and two equivalent O(1) atoms to form corner-sharing NbN2O4 octahedra. The corner-sharing octahedral tilt angles range from 22-43°. In the second Nb site, Nb(2) is bonded to two equivalent N(2), one O(2), one O(3), one O(4), and one O(5) atom to form distorted corner-sharing NbN2O4 octahedra. The corner-sharing octahedral tilt angles range from 19-43°. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 5-coordinate geometry to three equivalent La(2) and two equivalent Nb(1) atoms. In the second N site, N(2) is bonded in a distorted see-saw-like geometry to one La(1), one La(2), and two equivalent Nb(2) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent La(2) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded to two equivalent La(2), one Nb(1), and one Nb(2) atom to form OLa2Nb2 tetrahedra that share  a cornercorner with one O(3)La3Nb tetrahedra and corners with two equivalent O(2)La2Nb2 tetrahedra. In the third O site, O(3) is bonded to three equivalent La(1) and one Nb(2) atom to form distorted OLa3Nb tetrahedra that share  a cornercorner with one O(2)La2Nb2 tetrahedra and corners with six equivalent O(3)La3Nb tetrahedra. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent La(1), one Nb(1), and one Nb(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to three equivalent La(1) and one Nb(2) atom.
La2Nb2N2O5 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 9-coordinate geometry to one N(2), two equivalent O(4), three equivalent O(3), and three equivalent O(5) atoms. The La(1)-N(2) bond length is 2.71 Å. Both La(1)-O(4) bond lengths are 3.16 Å. There are two shorter (2.45 Å) and one longer (2.50 Å) La(1)-O(3) bond length. There are two shorter (2.54 Å) and one longer (2.76 Å) La(1)-O(5) bond length. In the second La site, La(2) is bonded in a 7-coordinate geometry to one N(2), three equivalent N(1), two equivalent O(1), and two equivalent O(2) atoms. The La(2)-N(2) bond length is 2.69 Å. There are two shorter (2.65 Å) and one longer (3.06 Å) La(2)-N(1) bond length. Both La(2)-O(1) bond lengths are 2.57 Å. Both La(2)-O(2) bond lengths are 2.46 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent N(1), one O(2), one O(4), and two equivalent O(1) atoms to form corner-sharing NbN2O4 octahedra. The corner-sharing octahedral tilt angles range from 22-43°. Both Nb(1)-N(1) bond lengths are 2.06 Å. The Nb(1)-O(2) bond length is 2.07 Å. The Nb(1)-O(4) bond length is 1.89 Å. There is one shorter (2.01 Å) and one longer (2.29 Å) Nb(1)-O(1) bond length. In the second Nb site, Nb(2) is bonded to two equivalent N(2), one O(2), one O(3), one O(4), and one O(5) atom to form distorted corner-sharing NbN2O4 octahedra. The corner-sharing octahedral tilt angles range from 19-43°. Both Nb(2)-N(2) bond lengths are 2.05 Å. The Nb(2)-O(2) bond length is 2.08 Å. The Nb(2)-O(3) bond length is 2.01 Å. The Nb(2)-O(4) bond length is 2.29 Å. The Nb(2)-O(5) bond length is 1.93 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 5-coordinate geometry to three equivalent La(2) and two equivalent Nb(1) atoms. In the second N site, N(2) is bonded in a distorted see-saw-like geometry to one La(1), one La(2), and two equivalent Nb(2) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent La(2) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded to two equivalent La(2), one Nb(1), and one Nb(2) atom to form OLa2Nb2 tetrahedra that share  a cornercorner with one O(3)La3Nb tetrahedra and corners with two equivalent O(2)La2Nb2 tetrahedra. In the third O site, O(3) is bonded to three equivalent La(1) and one Nb(2) atom to form distorted OLa3Nb tetrahedra that share  a cornercorner with one O(2)La2Nb2 tetrahedra and corners with six equivalent O(3)La3Nb tetrahedra. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent La(1), one Nb(1), and one Nb(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to three equivalent La(1) and one Nb(2) atom.