La3(NiO3)2 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. In the second La site, La(2) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. Ni(1) is bonded in a rectangular see-saw-like geometry to four equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent La(1), two equivalent La(2), and two equivalent Ni(1) atoms to form distorted OLa4Ni2 octahedra that share corners with eight equivalent O(1)La4Ni2 octahedra, corners with six equivalent O(2)La4 tetrahedra, edges with three equivalent O(1)La4Ni2 octahedra,  an edgeedge with one O(2)La4 tetrahedra, and faces with four equivalent O(1)La4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-67°. In the second O site, O(2) is bonded to four equivalent La(1) atoms to form OLa4 tetrahedra that share corners with twelve equivalent O(1)La4Ni2 octahedra, corners with four equivalent O(2)La4 tetrahedra, edges with two equivalent O(1)La4Ni2 octahedra, and edges with four equivalent O(2)La4 tetrahedra. The corner-sharing octahedral tilt angles range from 12-68°.
La3(NiO3)2 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All La(1)-O(1) bond lengths are 2.79 Å. All La(1)-O(2) bond lengths are 2.37 Å. In the second La site, La(2) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. All La(2)-O(1) bond lengths are 2.56 Å. Ni(1) is bonded in a rectangular see-saw-like geometry to four equivalent O(1) atoms. All Ni(1)-O(1) bond lengths are 2.00 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent La(1), two equivalent La(2), and two equivalent Ni(1) atoms to form distorted OLa4Ni2 octahedra that share corners with eight equivalent O(1)La4Ni2 octahedra, corners with six equivalent O(2)La4 tetrahedra, edges with three equivalent O(1)La4Ni2 octahedra,  an edgeedge with one O(2)La4 tetrahedra, and faces with four equivalent O(1)La4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-67°. In the second O site, O(2) is bonded to four equivalent La(1) atoms to form OLa4 tetrahedra that share corners with twelve equivalent O(1)La4Ni2 octahedra, corners with four equivalent O(2)La4 tetrahedra, edges with two equivalent O(1)La4Ni2 octahedra, and edges with four equivalent O(2)La4 tetrahedra. The corner-sharing octahedral tilt angles range from 12-68°.