Na3(CO4)2 crystallizes in the monoclinic C2/c 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(3) atoms to form edge-sharing NaO6 octahedra. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(2), one O(3), two equivalent O(1), and three equivalent O(4) atoms. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted see-saw-like geometry to three equivalent Na(2) and one O(4) atom. In the second O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Na(2) and one C(1) atom. In the third O site, O(2) is bonded in a distorted T-shaped geometry to one Na(1), one Na(2), and one C(1) atom. In the fourth O site, O(3) is bonded in a 4-coordinate geometry to one Na(2), two equivalent Na(1), and one C(1) atom.
Na3(CO4)2 crystallizes in the monoclinic C2/c 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(3) atoms to form edge-sharing NaO6 octahedra. Both Na(1)-O(2) bond lengths are 2.38 Å. There are two shorter (2.54 Å) and two longer (2.59 Å) Na(1)-O(3) bond lengths. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(2), one O(3), two equivalent O(1), and three equivalent O(4) atoms. The Na(2)-O(2) bond length is 2.42 Å. The Na(2)-O(3) bond length is 2.33 Å. There is one shorter (2.34 Å) and one longer (2.82 Å) Na(2)-O(1) bond length. There are a spread of Na(2)-O(4) bond distances ranging from 2.66-2.76 Å. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The C(1)-O(1) bond length is 1.29 Å. The C(1)-O(2) bond length is 1.29 Å. The C(1)-O(3) bond length is 1.29 Å. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted see-saw-like geometry to three equivalent Na(2) and one O(4) atom. The O(4)-O(4) bond length is 1.26 Å. In the second O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Na(2) and one C(1) atom. In the third O site, O(2) is bonded in a distorted T-shaped geometry to one Na(1), one Na(2), and one C(1) atom. In the fourth O site, O(3) is bonded in a 4-coordinate geometry to one Na(2), two equivalent Na(1), and one C(1) atom.