Na2CoO3 is Caswellsilverite-like structured and crystallizes in the orthorhombic Fddd space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, corners with two equivalent Co(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with five equivalent Na(2)O6 octahedra, and edges with five equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-19°. In the second Na site, Na(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with four equivalent Co(1)O6 octahedra, edges with three equivalent Na(2)O6 octahedra, edges with four equivalent Co(1)O6 octahedra, and edges with five equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-18°. Co(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CoO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with four equivalent Na(2)O6 octahedra, edges with three equivalent Co(1)O6 octahedra, edges with four equivalent Na(2)O6 octahedra, and edges with five equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-16°. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Co(1) atoms to form a mixture of distorted edge and corner-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. In the second O site, O(2) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Co(1) atoms to form a mixture of distorted edge and corner-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 5-14°.
Na2CoO3 is Caswellsilverite-like structured and crystallizes in the orthorhombic Fddd space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, corners with two equivalent Co(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with five equivalent Na(2)O6 octahedra, and edges with five equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-19°. Both Na(1)-O(2) bond lengths are 2.23 Å. There are two shorter (2.34 Å) and two longer (2.37 Å) Na(1)-O(1) bond lengths. In the second Na site, Na(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with four equivalent Co(1)O6 octahedra, edges with three equivalent Na(2)O6 octahedra, edges with four equivalent Co(1)O6 octahedra, and edges with five equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-18°. Both Na(2)-O(2) bond lengths are 2.40 Å. There are two shorter (2.20 Å) and two longer (2.41 Å) Na(2)-O(1) bond lengths. Co(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CoO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with four equivalent Na(2)O6 octahedra, edges with three equivalent Co(1)O6 octahedra, edges with four equivalent Na(2)O6 octahedra, and edges with five equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-16°. Both Co(1)-O(2) bond lengths are 1.98 Å. There are two shorter (1.85 Å) and two longer (2.01 Å) Co(1)-O(1) bond lengths. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Co(1) atoms to form a mixture of distorted edge and corner-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. In the second O site, O(2) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Co(1) atoms to form a mixture of distorted edge and corner-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 5-14°.