Cr3ZnP3O13 crystallizes in the monoclinic P2_1/m space group. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(5), one O(6), one O(9), and two equivalent O(8) atoms to form distorted CrO6 octahedra that share corners with two equivalent Cr(3)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  an edgeedge with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. In the second Cr site, Cr(2) is bonded to one O(1), one O(3), one O(7), and two equivalent O(2) atoms to form CrO5 square pyramids that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. In the third Cr site, Cr(3) is bonded to two equivalent O(10), two equivalent O(4), and two equivalent O(6) atoms to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and edges with two equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. Zn(1) is bonded in a 5-coordinate geometry to one O(9), two equivalent O(4), and two equivalent O(8) atoms. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(5), one O(7), and two equivalent O(2) atoms to form PO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra and corners with three equivalent Cr(2)O5 square pyramids. The corner-sharing octahedral tilt angles are 36°. In the second P site, P(2) is bonded to one O(10), one O(3), and two equivalent O(8) atoms to form PO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(3)O6 octahedra, and  a cornercorner with one Cr(2)O5 square pyramid. The corner-sharing octahedral tilt angles range from 46-54°. In the third P site, P(3) is bonded to one O(1), one O(9), and two equivalent O(4) atoms to form PO4 tetrahedra that share corners with two equivalent Cr(3)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid, and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are ten inequivalent O sites. In the first O site, O(10) is bonded in a distorted trigonal planar geometry to two equivalent Cr(3) and one P(2) atom. In the second O site, O(1) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(2), and one P(3) atom. In the third O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Cr(2) and one P(1) atom. In the fourth O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(2) and one P(2) atom. In the fifth O site, O(4) is bonded in a distorted trigonal planar geometry to one Cr(3), one Zn(1), and one P(3) atom. In the sixth O site, O(5) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the seventh O site, O(6) is bonded in a trigonal planar geometry to one Cr(1) and two equivalent Cr(3) atoms. In the eighth O site, O(7) is bonded in a bent 150 degrees geometry to one Cr(2) and one P(1) atom. In the ninth O site, O(8) is bonded in a 3-coordinate geometry to one Cr(1), one Zn(1), and one P(2) atom. In the tenth O site, O(9) is bonded in a 3-coordinate geometry to one Cr(1), one Zn(1), and one P(3) atom.
Cr3ZnP3O13 crystallizes in the monoclinic P2_1/m space group. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(5), one O(6), one O(9), and two equivalent O(8) atoms to form distorted CrO6 octahedra that share corners with two equivalent Cr(3)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  an edgeedge with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. The Cr(1)-O(1) bond length is 2.05 Å. The Cr(1)-O(5) bond length is 1.96 Å. The Cr(1)-O(6) bond length is 1.91 Å. The Cr(1)-O(9) bond length is 2.16 Å. Both Cr(1)-O(8) bond lengths are 1.99 Å. In the second Cr site, Cr(2) is bonded to one O(1), one O(3), one O(7), and two equivalent O(2) atoms to form CrO5 square pyramids that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. The Cr(2)-O(1) bond length is 1.95 Å. The Cr(2)-O(3) bond length is 1.94 Å. The Cr(2)-O(7) bond length is 1.91 Å. Both Cr(2)-O(2) bond lengths are 1.98 Å. In the third Cr site, Cr(3) is bonded to two equivalent O(10), two equivalent O(4), and two equivalent O(6) atoms to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and edges with two equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. Both Cr(3)-O(10) bond lengths are 2.06 Å. Both Cr(3)-O(4) bond lengths are 2.04 Å. Both Cr(3)-O(6) bond lengths are 2.00 Å. Zn(1) is bonded in a 5-coordinate geometry to one O(9), two equivalent O(4), and two equivalent O(8) atoms. The Zn(1)-O(9) bond length is 2.12 Å. Both Zn(1)-O(4) bond lengths are 2.42 Å. Both Zn(1)-O(8) bond lengths are 2.22 Å. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(5), one O(7), and two equivalent O(2) atoms to form PO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra and corners with three equivalent Cr(2)O5 square pyramids. The corner-sharing octahedral tilt angles are 36°. The P(1)-O(5) bond length is 1.54 Å. The P(1)-O(7) bond length is 1.54 Å. Both P(1)-O(2) bond lengths are 1.56 Å. In the second P site, P(2) is bonded to one O(10), one O(3), and two equivalent O(8) atoms to form PO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(3)O6 octahedra, and  a cornercorner with one Cr(2)O5 square pyramid. The corner-sharing octahedral tilt angles range from 46-54°. The P(2)-O(10) bond length is 1.57 Å. The P(2)-O(3) bond length is 1.51 Å. Both P(2)-O(8) bond lengths are 1.55 Å. In the third P site, P(3) is bonded to one O(1), one O(9), and two equivalent O(4) atoms to form PO4 tetrahedra that share corners with two equivalent Cr(3)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid, and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles are 53°. The P(3)-O(1) bond length is 1.55 Å. The P(3)-O(9) bond length is 1.56 Å. Both P(3)-O(4) bond lengths are 1.55 Å. There are ten inequivalent O sites. In the first O site, O(10) is bonded in a distorted trigonal planar geometry to two equivalent Cr(3) and one P(2) atom. In the second O site, O(1) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(2), and one P(3) atom. In the third O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Cr(2) and one P(1) atom. In the fourth O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(2) and one P(2) atom. In the fifth O site, O(4) is bonded in a distorted trigonal planar geometry to one Cr(3), one Zn(1), and one P(3) atom. In the sixth O site, O(5) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the seventh O site, O(6) is bonded in a trigonal planar geometry to one Cr(1) and two equivalent Cr(3) atoms. In the eighth O site, O(7) is bonded in a bent 150 degrees geometry to one Cr(2) and one P(1) atom. In the ninth O site, O(8) is bonded in a 3-coordinate geometry to one Cr(1), one Zn(1), and one P(2) atom. In the tenth O site, O(9) is bonded in a 3-coordinate geometry to one Cr(1), one Zn(1), and one P(3) atom.