K3NiO2 is Pb(Zr_(1-x)Ti_x)O3-like structured and crystallizes in the monoclinic P2_1 space group. There are six inequivalent K sites. In the first K site, K(1) is bonded in a distorted linear geometry to one O(1) and one O(3) atom. In the second K site, K(2) is bonded in a distorted linear geometry to one O(2) and one O(4) atom. In the third K site, K(3) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing KO4 tetrahedra. In the fourth K site, K(4) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing KO4 tetrahedra. In the fifth K site, K(5) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form a mixture of distorted corner and edge-sharing KO4 tetrahedra. In the sixth K site, K(6) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form a mixture of distorted corner and edge-sharing KO4 tetrahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a linear geometry to one O(2) and one O(4) atom. In the second Ni site, Ni(2) is bonded in a linear geometry to one O(1) and one O(3) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one K(1), one K(5), one K(6), two equivalent K(3), and one Ni(2) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one K(2), one K(5), one K(6), two equivalent K(4), and one Ni(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one K(1), one K(5), one K(6), two equivalent K(3), and one Ni(2) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one K(2), one K(5), one K(6), two equivalent K(4), and one Ni(1) atom.
K3NiO2 is Pb(Zr_(1-x)Ti_x)O3-like structured and crystallizes in the monoclinic P2_1 space group. There are six inequivalent K sites. In the first K site, K(1) is bonded in a distorted linear geometry to one O(1) and one O(3) atom. The K(1)-O(1) bond length is 2.55 Å. The K(1)-O(3) bond length is 2.55 Å. In the second K site, K(2) is bonded in a distorted linear geometry to one O(2) and one O(4) atom. The K(2)-O(2) bond length is 2.55 Å. The K(2)-O(4) bond length is 2.55 Å. In the third K site, K(3) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing KO4 tetrahedra. There is one shorter (2.78 Å) and one longer (2.82 Å) K(3)-O(1) bond length. There is one shorter (2.81 Å) and one longer (2.84 Å) K(3)-O(3) bond length. In the fourth K site, K(4) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing KO4 tetrahedra. There is one shorter (2.79 Å) and one longer (2.82 Å) K(4)-O(2) bond length. There is one shorter (2.80 Å) and one longer (2.84 Å) K(4)-O(4) bond length. In the fifth K site, K(5) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form a mixture of distorted corner and edge-sharing KO4 tetrahedra. The K(5)-O(1) bond length is 2.80 Å. The K(5)-O(2) bond length is 2.85 Å. The K(5)-O(3) bond length is 2.82 Å. The K(5)-O(4) bond length is 2.78 Å. In the sixth K site, K(6) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form a mixture of distorted corner and edge-sharing KO4 tetrahedra. The K(6)-O(1) bond length is 2.85 Å. The K(6)-O(2) bond length is 2.81 Å. The K(6)-O(3) bond length is 2.78 Å. The K(6)-O(4) bond length is 2.82 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a linear geometry to one O(2) and one O(4) atom. The Ni(1)-O(2) bond length is 1.80 Å. The Ni(1)-O(4) bond length is 1.80 Å. In the second Ni site, Ni(2) is bonded in a linear geometry to one O(1) and one O(3) atom. The Ni(2)-O(1) bond length is 1.80 Å. The Ni(2)-O(3) bond length is 1.80 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one K(1), one K(5), one K(6), two equivalent K(3), and one Ni(2) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one K(2), one K(5), one K(6), two equivalent K(4), and one Ni(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one K(1), one K(5), one K(6), two equivalent K(3), and one Ni(2) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one K(2), one K(5), one K(6), two equivalent K(4), and one Ni(1) atom.