Li4CoNi5O12 crystallizes in the monoclinic C2/m space group. Li(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. Co(1) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form CoO6 octahedra that share edges with six equivalent Ni(2)O6 octahedra. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form edge-sharing NiO6 octahedra. In the second Ni site, Ni(2) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form NiO6 octahedra that share edges with three equivalent Co(1)O6 octahedra and edges with three equivalent Ni(2)O6 octahedra. In the third Ni site, Ni(3) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form edge-sharing NiO6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(1), one Co(1), and two equivalent Ni(2) atoms to form distorted OLi2CoNi2 square pyramids that share corners with two equivalent O(2)Li2Ni3 square pyramids, corners with three equivalent O(1)Li2CoNi2 square pyramids,  an edgeedge with one O(2)Li2Ni3 square pyramid, and edges with four equivalent O(1)Li2CoNi2 square pyramids. In the second O site, O(2) is bonded to two equivalent Li(1), one Ni(3), and two equivalent Ni(1) atoms to form distorted OLi2Ni3 square pyramids that share corners with two equivalent O(1)Li2CoNi2 square pyramids, corners with three equivalent O(2)Li2Ni3 square pyramids,  an edgeedge with one O(1)Li2CoNi2 square pyramid, and edges with four equivalent O(2)Li2Ni3 square pyramids. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Ni(3) and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Co(1) and two equivalent Ni(2) atoms.
Li4CoNi5O12 crystallizes in the monoclinic C2/m space group. Li(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. There is one shorter (2.01 Å) and one longer (2.05 Å) Li(1)-O(1) bond length. There is one shorter (2.01 Å) and one longer (2.07 Å) Li(1)-O(2) bond length. Co(1) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form CoO6 octahedra that share edges with six equivalent Ni(2)O6 octahedra. Both Co(1)-O(4) bond lengths are 1.91 Å. All Co(1)-O(1) bond lengths are 1.92 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form edge-sharing NiO6 octahedra. Both Ni(1)-O(3) bond lengths are 1.94 Å. There are two shorter (1.86 Å) and two longer (2.03 Å) Ni(1)-O(2) bond lengths. In the second Ni site, Ni(2) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form NiO6 octahedra that share edges with three equivalent Co(1)O6 octahedra and edges with three equivalent Ni(2)O6 octahedra. Both Ni(2)-O(4) bond lengths are 1.88 Å. There are two shorter (1.92 Å) and two longer (2.05 Å) Ni(2)-O(1) bond lengths. In the third Ni site, Ni(3) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form edge-sharing NiO6 octahedra. Both Ni(3)-O(3) bond lengths are 1.90 Å. All Ni(3)-O(2) bond lengths are 1.98 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(1), one Co(1), and two equivalent Ni(2) atoms to form distorted OLi2CoNi2 square pyramids that share corners with two equivalent O(2)Li2Ni3 square pyramids, corners with three equivalent O(1)Li2CoNi2 square pyramids,  an edgeedge with one O(2)Li2Ni3 square pyramid, and edges with four equivalent O(1)Li2CoNi2 square pyramids. In the second O site, O(2) is bonded to two equivalent Li(1), one Ni(3), and two equivalent Ni(1) atoms to form distorted OLi2Ni3 square pyramids that share corners with two equivalent O(1)Li2CoNi2 square pyramids, corners with three equivalent O(2)Li2Ni3 square pyramids,  an edgeedge with one O(1)Li2CoNi2 square pyramid, and edges with four equivalent O(2)Li2Ni3 square pyramids. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Ni(3) and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Co(1) and two equivalent Ni(2) atoms.