Zn4P2O13 crystallizes in the monoclinic P2/c space group. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form distorted ZnO6 octahedra that share corners with two equivalent Zn(3)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and faces with two equivalent Zn(2)O6 octahedra. In the second Zn site, Zn(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form distorted ZnO6 octahedra that share corners with two equivalent Zn(3)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and faces with two equivalent Zn(1)O6 octahedra. In the third Zn site, Zn(3) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form ZnO4 tetrahedra that share  a cornercorner with one Zn(1)O6 octahedra,  a cornercorner with one Zn(2)O6 octahedra, and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-60°. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Zn(1)O6 octahedra, corners with two equivalent Zn(2)O6 octahedra, and corners with two equivalent Zn(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-46°. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a bent 120 degrees geometry to one Zn(3) and one O(7) atom. In the second O site, O(7) is bonded in a bent 120 degrees geometry to two equivalent O(6) atoms. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Zn(1), one Zn(2), and one P(1) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Zn(1), one Zn(2), and one P(1) atom. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one Zn(3) and one P(1) atom. In the sixth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Zn(3) and one P(1) atom. In the seventh O site, O(5) is bonded in a distorted trigonal planar geometry to one Zn(1), one Zn(2), and one Zn(3) atom.
Zn4P2O13 crystallizes in the monoclinic P2/c space group. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form distorted ZnO6 octahedra that share corners with two equivalent Zn(3)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and faces with two equivalent Zn(2)O6 octahedra. Both Zn(1)-O(1) bond lengths are 2.20 Å. Both Zn(1)-O(2) bond lengths are 2.06 Å. Both Zn(1)-O(5) bond lengths are 2.01 Å. In the second Zn site, Zn(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form distorted ZnO6 octahedra that share corners with two equivalent Zn(3)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and faces with two equivalent Zn(1)O6 octahedra. Both Zn(2)-O(1) bond lengths are 2.09 Å. Both Zn(2)-O(2) bond lengths are 2.26 Å. Both Zn(2)-O(5) bond lengths are 1.99 Å. In the third Zn site, Zn(3) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form ZnO4 tetrahedra that share  a cornercorner with one Zn(1)O6 octahedra,  a cornercorner with one Zn(2)O6 octahedra, and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-60°. The Zn(3)-O(3) bond length is 1.91 Å. The Zn(3)-O(4) bond length is 1.91 Å. The Zn(3)-O(5) bond length is 1.92 Å. The Zn(3)-O(6) bond length is 2.19 Å. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Zn(1)O6 octahedra, corners with two equivalent Zn(2)O6 octahedra, and corners with two equivalent Zn(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-46°. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(2) bond length is 1.57 Å. The P(1)-O(3) bond length is 1.55 Å. The P(1)-O(4) bond length is 1.54 Å. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a bent 120 degrees geometry to one Zn(3) and one O(7) atom. The O(6)-O(7) bond length is 1.32 Å. In the second O site, O(7) is bonded in a bent 120 degrees geometry to two equivalent O(6) atoms. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Zn(1), one Zn(2), and one P(1) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Zn(1), one Zn(2), and one P(1) atom. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one Zn(3) and one P(1) atom. In the sixth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Zn(3) and one P(1) atom. In the seventh O site, O(5) is bonded in a distorted trigonal planar geometry to one Zn(1), one Zn(2), and one Zn(3) atom.