Na2CrO4 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. In the second Na site, Na(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form NaO6 octahedra that share corners with six equivalent Cr(1)O4 tetrahedra and edges with two equivalent Na(2)O6 octahedra. Cr(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form CrO4 tetrahedra that share corners with six equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-52°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), and one Cr(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(2), and one Cr(1) atom.
Na2CrO4 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Na(1)-O(1) bond lengths are 2.28 Å. Both Na(1)-O(2) bond lengths are 2.46 Å. In the second Na site, Na(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form NaO6 octahedra that share corners with six equivalent Cr(1)O4 tetrahedra and edges with two equivalent Na(2)O6 octahedra. Both Na(2)-O(1) bond lengths are 2.32 Å. All Na(2)-O(2) bond lengths are 2.39 Å. Cr(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form CrO4 tetrahedra that share corners with six equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-52°. Both Cr(1)-O(1) bond lengths are 1.64 Å. Both Cr(1)-O(2) bond lengths are 1.66 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), and one Cr(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(2), and one Cr(1) atom.