Li2NiCuO4 crystallizes in the monoclinic C2/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and four equivalent O(1) atoms. In the second Li site, Li(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form LiO6 octahedra that share edges with two equivalent Li(2)O6 octahedra and edges with four equivalent Ni(1)O6 octahedra. Ni(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NiO6 octahedra that share edges with two equivalent Ni(1)O6 octahedra and edges with four equivalent Li(2)O6 octahedra. Cu(1) is bonded in a distorted square co-planar geometry to two equivalent O(1) and four equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Li(2), two equivalent Li(1), two equivalent Ni(1), and one Cu(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Li(1), two equivalent Li(2), one Ni(1), and two equivalent Cu(1) atoms.
Li2NiCuO4 crystallizes in the monoclinic C2/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and four equivalent O(1) atoms. Both Li(1)-O(2) bond lengths are 2.08 Å. There are two shorter (2.03 Å) and two longer (2.58 Å) Li(1)-O(1) bond lengths. In the second Li site, Li(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form LiO6 octahedra that share edges with two equivalent Li(2)O6 octahedra and edges with four equivalent Ni(1)O6 octahedra. Both Li(2)-O(1) bond lengths are 2.12 Å. There are two shorter (2.03 Å) and two longer (2.26 Å) Li(2)-O(2) bond lengths. Ni(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NiO6 octahedra that share edges with two equivalent Ni(1)O6 octahedra and edges with four equivalent Li(2)O6 octahedra. Both Ni(1)-O(2) bond lengths are 1.91 Å. There are two shorter (1.97 Å) and two longer (2.13 Å) Ni(1)-O(1) bond lengths. Cu(1) is bonded in a distorted square co-planar geometry to two equivalent O(1) and four equivalent O(2) atoms. Both Cu(1)-O(1) bond lengths are 1.87 Å. There are two shorter (1.87 Å) and two longer (2.53 Å) Cu(1)-O(2) bond lengths. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Li(2), two equivalent Li(1), two equivalent Ni(1), and one Cu(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Li(1), two equivalent Li(2), one Ni(1), and two equivalent Cu(1) atoms.