Na3CrCPO7 crystallizes in the monoclinic P2_1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form NaO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra, and edges with two equivalent Cr(1)O5 trigonal bipyramids. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(6) atom. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms. Cr(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form distorted CrO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra and edges with two equivalent Na(1)O6 octahedra. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(5) atom. P(1) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra and corners with three equivalent Cr(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 49-54°. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), two equivalent Na(1), and one C(1) atom to form distorted corner-sharing ONa3C tetrahedra. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one Cr(1), and one C(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Cr(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Cr(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Na(3), one Cr(1), and one C(1) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), two equivalent Na(3), and one P(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Na(3), one Cr(1), and one P(1) atom.
Na3CrCPO7 crystallizes in the monoclinic P2_1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form NaO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra, and edges with two equivalent Cr(1)O5 trigonal bipyramids. The Na(1)-O(3) bond length is 2.45 Å. The Na(1)-O(4) bond length is 2.40 Å. There is one shorter (2.42 Å) and one longer (2.43 Å) Na(1)-O(1) bond length. There is one shorter (2.36 Å) and one longer (2.37 Å) Na(1)-O(2) bond length. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(6) atom. The Na(2)-O(1) bond length is 2.32 Å. The Na(2)-O(2) bond length is 2.69 Å. The Na(2)-O(3) bond length is 2.43 Å. The Na(2)-O(4) bond length is 2.58 Å. The Na(2)-O(6) bond length is 2.29 Å. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms. There is one shorter (2.55 Å) and one longer (2.77 Å) Na(3)-O(5) bond length. There is one shorter (2.28 Å) and one longer (2.30 Å) Na(3)-O(6) bond length. There is one shorter (2.52 Å) and one longer (2.59 Å) Na(3)-O(7) bond length. Cr(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form distorted CrO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra and edges with two equivalent Na(1)O6 octahedra. The Cr(1)-O(2) bond length is 2.36 Å. The Cr(1)-O(3) bond length is 2.07 Å. The Cr(1)-O(4) bond length is 2.08 Å. The Cr(1)-O(5) bond length is 2.18 Å. The Cr(1)-O(7) bond length is 2.16 Å. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(5) atom. The C(1)-O(1) bond length is 1.30 Å. The C(1)-O(2) bond length is 1.31 Å. The C(1)-O(5) bond length is 1.30 Å. P(1) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra and corners with three equivalent Cr(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 49-54°. The P(1)-O(3) bond length is 1.57 Å. The P(1)-O(4) bond length is 1.57 Å. The P(1)-O(6) bond length is 1.54 Å. The P(1)-O(7) bond length is 1.55 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), two equivalent Na(1), and one C(1) atom to form distorted corner-sharing ONa3C tetrahedra. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one Cr(1), and one C(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Cr(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Cr(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Na(3), one Cr(1), and one C(1) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), two equivalent Na(3), and one P(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Na(3), one Cr(1), and one P(1) atom.