NaCo3O4 is Enargite structured and crystallizes in the orthorhombic Pmn2_1 space group. Na(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form distorted NaO4 tetrahedra that share corners with four equivalent Co(1)O4 tetrahedra and corners with eight equivalent Co(2)O4 tetrahedra. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form CoO4 tetrahedra that share corners with four equivalent Na(1)O4 tetrahedra and corners with eight equivalent Co(2)O4 tetrahedra. In the second Co site, Co(2) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form CoO4 tetrahedra that share corners with four equivalent Na(1)O4 tetrahedra, corners with four equivalent Co(1)O4 tetrahedra, and corners with four equivalent Co(2)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Co(1), and two equivalent Co(2) atoms to form corner-sharing ONaCo3 tetrahedra. In the second O site, O(2) is bonded to one Na(1), one Co(1), and two equivalent Co(2) atoms to form distorted corner-sharing ONaCo3 trigonal pyramids. In the third O site, O(3) is bonded to one Na(1), one Co(1), and two equivalent Co(2) atoms to form corner-sharing ONaCo3 tetrahedra.
NaCo3O4 is Enargite structured and crystallizes in the orthorhombic Pmn2_1 space group. Na(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form distorted NaO4 tetrahedra that share corners with four equivalent Co(1)O4 tetrahedra and corners with eight equivalent Co(2)O4 tetrahedra. The Na(1)-O(1) bond length is 2.31 Å. The Na(1)-O(2) bond length is 2.39 Å. Both Na(1)-O(3) bond lengths are 2.29 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form CoO4 tetrahedra that share corners with four equivalent Na(1)O4 tetrahedra and corners with eight equivalent Co(2)O4 tetrahedra. The Co(1)-O(1) bond length is 1.90 Å. The Co(1)-O(2) bond length is 1.90 Å. Both Co(1)-O(3) bond lengths are 1.88 Å. In the second Co site, Co(2) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form CoO4 tetrahedra that share corners with four equivalent Na(1)O4 tetrahedra, corners with four equivalent Co(1)O4 tetrahedra, and corners with four equivalent Co(2)O4 tetrahedra. The Co(2)-O(1) bond length is 1.99 Å. The Co(2)-O(2) bond length is 2.01 Å. There is one shorter (1.98 Å) and one longer (1.99 Å) Co(2)-O(3) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Co(1), and two equivalent Co(2) atoms to form corner-sharing ONaCo3 tetrahedra. In the second O site, O(2) is bonded to one Na(1), one Co(1), and two equivalent Co(2) atoms to form distorted corner-sharing ONaCo3 trigonal pyramids. In the third O site, O(3) is bonded to one Na(1), one Co(1), and two equivalent Co(2) atoms to form corner-sharing ONaCo3 tetrahedra.