NaCu3O4 crystallizes in the tetragonal P4_122 space group. Na(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form NaO6 octahedra that share corners with two equivalent Cu(3)O6 octahedra, corners with four equivalent Cu(2)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Cu(2)O6 octahedra, edges with four equivalent Cu(1)O6 octahedra, and edges with four equivalent Cu(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-15°. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted CuO6 octahedra that share corners with two equivalent Cu(2)O6 octahedra, corners with four equivalent Cu(3)O6 octahedra, edges with two equivalent Cu(1)O6 octahedra, edges with two equivalent Cu(3)O6 octahedra, edges with four equivalent Na(1)O6 octahedra, and edges with four equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-19°. In the second Cu site, Cu(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted CuO6 octahedra that share corners with two equivalent Cu(1)O6 octahedra, corners with four equivalent Na(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Cu(2)O6 octahedra, edges with four equivalent Cu(1)O6 octahedra, and edges with four equivalent Cu(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-15°. In the third Cu site, Cu(3) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CuO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with four equivalent Cu(1)O6 octahedra, edges with two equivalent Cu(1)O6 octahedra, edges with two equivalent Cu(3)O6 octahedra, edges with four equivalent Na(1)O6 octahedra, and edges with four equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-19°. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Cu(3), two equivalent Cu(1), and two equivalent Cu(2) atoms to form distorted ONaCu5 octahedra that share corners with two equivalent O(1)NaCu5 octahedra, corners with four equivalent O(2)Na2Cu4 octahedra, edges with six equivalent O(2)Na2Cu4 octahedra, and edges with six equivalent O(1)NaCu5 octahedra. The corner-sharing octahedral tilt angles range from 6-14°. In the second O site, O(2) is bonded to two equivalent Na(1), one Cu(1), one Cu(2), and two equivalent Cu(3) atoms to form ONa2Cu4 octahedra that share corners with two equivalent O(2)Na2Cu4 octahedra, corners with four equivalent O(1)NaCu5 octahedra, edges with six equivalent O(2)Na2Cu4 octahedra, and edges with six equivalent O(1)NaCu5 octahedra. The corner-sharing octahedral tilt angles range from 6-14°.
NaCu3O4 crystallizes in the tetragonal P4_122 space group. Na(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form NaO6 octahedra that share corners with two equivalent Cu(3)O6 octahedra, corners with four equivalent Cu(2)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Cu(2)O6 octahedra, edges with four equivalent Cu(1)O6 octahedra, and edges with four equivalent Cu(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-15°. Both Na(1)-O(1) bond lengths are 2.35 Å. There are two shorter (2.35 Å) and two longer (2.41 Å) Na(1)-O(2) bond lengths. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted CuO6 octahedra that share corners with two equivalent Cu(2)O6 octahedra, corners with four equivalent Cu(3)O6 octahedra, edges with two equivalent Cu(1)O6 octahedra, edges with two equivalent Cu(3)O6 octahedra, edges with four equivalent Na(1)O6 octahedra, and edges with four equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-19°. Both Cu(1)-O(2) bond lengths are 2.19 Å. There are two shorter (1.92 Å) and two longer (2.17 Å) Cu(1)-O(1) bond lengths. In the second Cu site, Cu(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted CuO6 octahedra that share corners with two equivalent Cu(1)O6 octahedra, corners with four equivalent Na(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Cu(2)O6 octahedra, edges with four equivalent Cu(1)O6 octahedra, and edges with four equivalent Cu(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-15°. Both Cu(2)-O(2) bond lengths are 1.95 Å. There are two shorter (1.95 Å) and two longer (2.49 Å) Cu(2)-O(1) bond lengths. In the third Cu site, Cu(3) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CuO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with four equivalent Cu(1)O6 octahedra, edges with two equivalent Cu(1)O6 octahedra, edges with two equivalent Cu(3)O6 octahedra, edges with four equivalent Na(1)O6 octahedra, and edges with four equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-19°. Both Cu(3)-O(1) bond lengths are 2.13 Å. There are two shorter (2.01 Å) and two longer (2.15 Å) Cu(3)-O(2) bond lengths. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Cu(3), two equivalent Cu(1), and two equivalent Cu(2) atoms to form distorted ONaCu5 octahedra that share corners with two equivalent O(1)NaCu5 octahedra, corners with four equivalent O(2)Na2Cu4 octahedra, edges with six equivalent O(2)Na2Cu4 octahedra, and edges with six equivalent O(1)NaCu5 octahedra. The corner-sharing octahedral tilt angles range from 6-14°. In the second O site, O(2) is bonded to two equivalent Na(1), one Cu(1), one Cu(2), and two equivalent Cu(3) atoms to form ONa2Cu4 octahedra that share corners with two equivalent O(2)Na2Cu4 octahedra, corners with four equivalent O(1)NaCu5 octahedra, edges with six equivalent O(2)Na2Cu4 octahedra, and edges with six equivalent O(1)NaCu5 octahedra. The corner-sharing octahedral tilt angles range from 6-14°.