Li2Mn(NiO3)2 crystallizes in the monoclinic C2 space group. Li(1) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form LiO6 octahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with five equivalent Ni(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-16°. Mn(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form MnO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 5°. Ni(1) is bonded to one O(2), two equivalent O(1), and three equivalent O(3) atoms to form NiO6 octahedra that share corners with five equivalent Li(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-16°. There are three inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Li(1), one Mn(1), and two equivalent Ni(1) atoms to form OLi3MnNi2 octahedra that share  a cornercorner with one O(1)Li3MnNi2 octahedra, corners with four equivalent O(3)Li2Ni3 square pyramids, edges with four equivalent O(1)Li3MnNi2 octahedra, and edges with four equivalent O(3)Li2Ni3 square pyramids. The corner-sharing octahedral tilt angles are 4°. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Li(1), two equivalent Mn(1), and one Ni(1) atom. In the third O site, O(3) is bonded to two equivalent Li(1) and three equivalent Ni(1) atoms to form OLi2Ni3 square pyramids that share corners with four equivalent O(1)Li3MnNi2 octahedra, edges with four equivalent O(1)Li3MnNi2 octahedra, and edges with four equivalent O(3)Li2Ni3 square pyramids. The corner-sharing octahedral tilt angles range from 2-7°.
Li2Mn(NiO3)2 crystallizes in the monoclinic C2 space group. Li(1) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form LiO6 octahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with five equivalent Ni(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-16°. The Li(1)-O(2) bond length is 2.11 Å. There is one shorter (2.02 Å) and one longer (2.17 Å) Li(1)-O(3) bond length. There are a spread of Li(1)-O(1) bond distances ranging from 2.13-2.30 Å. Mn(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form MnO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 5°. Both Mn(1)-O(1) bond lengths are 1.92 Å. All Mn(1)-O(2) bond lengths are 1.94 Å. Ni(1) is bonded to one O(2), two equivalent O(1), and three equivalent O(3) atoms to form NiO6 octahedra that share corners with five equivalent Li(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-16°. The Ni(1)-O(2) bond length is 1.94 Å. There is one shorter (1.96 Å) and one longer (2.14 Å) Ni(1)-O(1) bond length. There are a spread of Ni(1)-O(3) bond distances ranging from 1.89-2.08 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Li(1), one Mn(1), and two equivalent Ni(1) atoms to form OLi3MnNi2 octahedra that share  a cornercorner with one O(1)Li3MnNi2 octahedra, corners with four equivalent O(3)Li2Ni3 square pyramids, edges with four equivalent O(1)Li3MnNi2 octahedra, and edges with four equivalent O(3)Li2Ni3 square pyramids. The corner-sharing octahedral tilt angles are 4°. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Li(1), two equivalent Mn(1), and one Ni(1) atom. In the third O site, O(3) is bonded to two equivalent Li(1) and three equivalent Ni(1) atoms to form OLi2Ni3 square pyramids that share corners with four equivalent O(1)Li3MnNi2 octahedra, edges with four equivalent O(1)Li3MnNi2 octahedra, and edges with four equivalent O(3)Li2Ni3 square pyramids. The corner-sharing octahedral tilt angles range from 2-7°.