K2NiO2 crystallizes in the tetragonal I4/mmm space group. K(1) is bonded to five equivalent O(1) atoms to form a mixture of corner and edge-sharing KO5 square pyramids. Ni(1) is bonded in a linear geometry to two equivalent O(1) atoms. O(1) is bonded to five equivalent K(1) and one Ni(1) atom to form a mixture of distorted corner and edge-sharing OK5Ni octahedra. The corner-sharing octahedral tilt angles range from 0-11°.
K2NiO2 crystallizes in the tetragonal I4/mmm space group. K(1) is bonded to five equivalent O(1) atoms to form a mixture of corner and edge-sharing KO5 square pyramids. There is one shorter (2.71 Å) and four longer (2.79 Å) K(1)-O(1) bond lengths. Ni(1) is bonded in a linear geometry to two equivalent O(1) atoms. Both Ni(1)-O(1) bond lengths are 1.69 Å. O(1) is bonded to five equivalent K(1) and one Ni(1) atom to form a mixture of distorted corner and edge-sharing OK5Ni octahedra. The corner-sharing octahedral tilt angles range from 0-11°.