Na5CrO4 crystallizes in the orthorhombic Pmmn space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form NaO4 tetrahedra that share corners with four equivalent Cr(1)O4 tetrahedra. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. Cr(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form CrO4 tetrahedra that share corners with four equivalent Na(1)O4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), four equivalent Na(2), and one Cr(1) atom to form a mixture of corner and edge-sharing ONa5Cr octahedra. The corner-sharing octahedral tilt angles range from 58-59°. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), four equivalent Na(2), and one Cr(1) atom.
Na5CrO4 crystallizes in the orthorhombic Pmmn space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form NaO4 tetrahedra that share corners with four equivalent Cr(1)O4 tetrahedra. Both Na(1)-O(1) bond lengths are 2.39 Å. Both Na(1)-O(2) bond lengths are 2.33 Å. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. There is one shorter (2.32 Å) and one longer (2.36 Å) Na(2)-O(1) bond length. There is one shorter (2.36 Å) and one longer (2.48 Å) Na(2)-O(2) bond length. Cr(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form CrO4 tetrahedra that share corners with four equivalent Na(1)O4 tetrahedra. Both Cr(1)-O(1) bond lengths are 1.99 Å. Both Cr(1)-O(2) bond lengths are 1.91 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), four equivalent Na(2), and one Cr(1) atom to form a mixture of corner and edge-sharing ONa5Cr octahedra. The corner-sharing octahedral tilt angles range from 58-59°. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), four equivalent Na(2), and one Cr(1) atom.