Na2NiO2 crystallizes in the tetragonal I4/mmm space group. Na(1) is bonded to four equivalent O(1) atoms to form a mixture of distorted edge and corner-sharing NaO4 trigonal pyramids. Ni(1) is bonded in a linear geometry to two equivalent O(1) atoms. O(1) is bonded in a 5-coordinate geometry to four equivalent Na(1) and one Ni(1) atom.
Na2NiO2 crystallizes in the tetragonal I4/mmm space group. Na(1) is bonded to four equivalent O(1) atoms to form a mixture of distorted edge and corner-sharing NaO4 trigonal pyramids. All Na(1)-O(1) bond lengths are 2.35 Å. Ni(1) is bonded in a linear geometry to two equivalent O(1) atoms. Both Ni(1)-O(1) bond lengths are 1.73 Å. O(1) is bonded in a 5-coordinate geometry to four equivalent Na(1) and one Ni(1) atom.