Ca(NiO2)4 is beta indium sulfide-derived structured and crystallizes in the trigonal R-3m space group. Ca(1) is bonded in a distorted hexagonal planar geometry to six equivalent O(2) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to six equivalent O(2) atoms to form edge-sharing NiO6 octahedra. In the second Ni site, Ni(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing NiO6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to three equivalent Ni(2) atoms. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ni(1), and two equivalent Ni(2) atoms.
Ca(NiO2)4 is beta indium sulfide-derived structured and crystallizes in the trigonal R-3m space group. Ca(1) is bonded in a distorted hexagonal planar geometry to six equivalent O(2) atoms. All Ca(1)-O(2) bond lengths are 2.36 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to six equivalent O(2) atoms to form edge-sharing NiO6 octahedra. All Ni(1)-O(2) bond lengths are 1.99 Å. In the second Ni site, Ni(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing NiO6 octahedra. Both Ni(2)-O(1) bond lengths are 1.89 Å. All Ni(2)-O(2) bond lengths are 1.87 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to three equivalent Ni(2) atoms. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ni(1), and two equivalent Ni(2) atoms.