La3IrO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. In the second La site, La(2) is bonded to one O(3), two equivalent O(2), and four equivalent O(1) atoms to form distorted LaO7 pentagonal bipyramids that share corners with two equivalent Ir(1)O6 octahedra, corners with three equivalent La(2)O7 pentagonal bipyramids, edges with two equivalent Ir(1)O6 octahedra, and edges with two equivalent La(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 32°. Ir(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form IrO6 octahedra that share corners with two equivalent Ir(1)O6 octahedra, corners with four equivalent La(2)O7 pentagonal bipyramids, and edges with four equivalent La(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 40°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one La(1), two equivalent La(2), and one Ir(1) atom. In the second O site, O(2) is bonded to two equivalent La(1) and two equivalent La(2) atoms to form OLa4 tetrahedra that share corners with six equivalent O(2)La4 tetrahedra, corners with two equivalent O(3)La2Ir2 trigonal pyramids, and  an edgeedge with one O(2)La4 tetrahedra. In the third O site, O(3) is bonded to two equivalent La(2) and two equivalent Ir(1) atoms to form distorted OLa2Ir2 trigonal pyramids that share corners with four equivalent O(2)La4 tetrahedra and corners with two equivalent O(3)La2Ir2 trigonal pyramids.
La3IrO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All La(1)-O(1) bond lengths are 2.78 Å. All La(1)-O(2) bond lengths are 2.41 Å. In the second La site, La(2) is bonded to one O(3), two equivalent O(2), and four equivalent O(1) atoms to form distorted LaO7 pentagonal bipyramids that share corners with two equivalent Ir(1)O6 octahedra, corners with three equivalent La(2)O7 pentagonal bipyramids, edges with two equivalent Ir(1)O6 octahedra, and edges with two equivalent La(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 32°. The La(2)-O(3) bond length is 2.58 Å. There is one shorter (2.32 Å) and one longer (2.35 Å) La(2)-O(2) bond length. There are two shorter (2.47 Å) and two longer (2.54 Å) La(2)-O(1) bond lengths. Ir(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form IrO6 octahedra that share corners with two equivalent Ir(1)O6 octahedra, corners with four equivalent La(2)O7 pentagonal bipyramids, and edges with four equivalent La(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 40°. Both Ir(1)-O(3) bond lengths are 2.03 Å. All Ir(1)-O(1) bond lengths are 1.98 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one La(1), two equivalent La(2), and one Ir(1) atom. In the second O site, O(2) is bonded to two equivalent La(1) and two equivalent La(2) atoms to form OLa4 tetrahedra that share corners with six equivalent O(2)La4 tetrahedra, corners with two equivalent O(3)La2Ir2 trigonal pyramids, and  an edgeedge with one O(2)La4 tetrahedra. In the third O site, O(3) is bonded to two equivalent La(2) and two equivalent Ir(1) atoms to form distorted OLa2Ir2 trigonal pyramids that share corners with four equivalent O(2)La4 tetrahedra and corners with two equivalent O(3)La2Ir2 trigonal pyramids.