Na2ZnP2O7 crystallizes in the tetragonal P4_2/mnm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. Zn(1) is bonded to four equivalent O(1) atoms to form ZnO4 tetrahedra that share corners with four equivalent P(1)O4 tetrahedra. P(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Zn(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(2), and one P(1) atom. In the second O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Na(1) and two equivalent P(1) atoms. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Zn(1), and one P(1) atom.
Na2ZnP2O7 crystallizes in the tetragonal P4_2/mnm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Both Na(1)-O(2) bond lengths are 2.40 Å. Both Na(1)-O(3) bond lengths are 2.69 Å. All Na(1)-O(1) bond lengths are 2.78 Å. In the second Na site, Na(2) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Na(2)-O(1) bond lengths are 2.66 Å. All Na(2)-O(2) bond lengths are 2.67 Å. Zn(1) is bonded to four equivalent O(1) atoms to form ZnO4 tetrahedra that share corners with four equivalent P(1)O4 tetrahedra. All Zn(1)-O(1) bond lengths are 1.97 Å. P(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Zn(1)O4 tetrahedra. The P(1)-O(2) bond length is 1.51 Å. The P(1)-O(3) bond length is 1.64 Å. Both P(1)-O(1) bond lengths are 1.54 Å. There are three inequivalent O sites. In the first O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(2), and one P(1) atom. In the second O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Na(1) and two equivalent P(1) atoms. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Zn(1), and one P(1) atom.