NaInP2O7 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form distorted NaO6 pentagonal pyramids that share corners with three equivalent In(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one In(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-67°. In(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form InO6 octahedra that share corners with three equivalent Na(1)O6 pentagonal pyramids, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Na(1)O6 pentagonal pyramid. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent In(1)O6 octahedra, corners with two equivalent Na(1)O6 pentagonal pyramids,  a cornercorner with one P(2)O4 tetrahedra, and  an edgeedge with one Na(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 33-57°. In the second P site, P(2) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share corners with three equivalent In(1)O6 octahedra, corners with three equivalent Na(1)O6 pentagonal pyramids, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 22-56°. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a distorted trigonal planar geometry to one Na(1), one In(1), and one P(1) atom. In the second O site, O(7) is bonded in a 3-coordinate geometry to one Na(1), one In(1), and one P(1) atom. In the third O site, O(1) is bonded in a distorted trigonal planar geometry to one Na(1), one In(1), and one P(1) atom. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to one Na(1), one In(1), and one P(2) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one P(1), and one P(2) atom. In the sixth O site, O(4) is bonded in a bent 150 degrees geometry to one In(1) and one P(2) atom. In the seventh O site, O(5) is bonded in a distorted trigonal planar geometry to one Na(1), one In(1), and one P(2) atom.
NaInP2O7 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form distorted NaO6 pentagonal pyramids that share corners with three equivalent In(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one In(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-67°. The Na(1)-O(1) bond length is 2.46 Å. The Na(1)-O(2) bond length is 2.43 Å. The Na(1)-O(3) bond length is 2.55 Å. The Na(1)-O(5) bond length is 2.53 Å. The Na(1)-O(6) bond length is 2.66 Å. The Na(1)-O(7) bond length is 2.43 Å. In(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form InO6 octahedra that share corners with three equivalent Na(1)O6 pentagonal pyramids, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Na(1)O6 pentagonal pyramid. The In(1)-O(1) bond length is 2.16 Å. The In(1)-O(2) bond length is 2.17 Å. The In(1)-O(4) bond length is 2.09 Å. The In(1)-O(5) bond length is 2.14 Å. The In(1)-O(6) bond length is 2.17 Å. The In(1)-O(7) bond length is 2.12 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent In(1)O6 octahedra, corners with two equivalent Na(1)O6 pentagonal pyramids,  a cornercorner with one P(2)O4 tetrahedra, and  an edgeedge with one Na(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 33-57°. The P(1)-O(1) bond length is 1.53 Å. The P(1)-O(3) bond length is 1.61 Å. The P(1)-O(6) bond length is 1.52 Å. The P(1)-O(7) bond length is 1.50 Å. In the second P site, P(2) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share corners with three equivalent In(1)O6 octahedra, corners with three equivalent Na(1)O6 pentagonal pyramids, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 22-56°. The P(2)-O(2) bond length is 1.52 Å. The P(2)-O(3) bond length is 1.61 Å. The P(2)-O(4) bond length is 1.49 Å. The P(2)-O(5) bond length is 1.52 Å. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a distorted trigonal planar geometry to one Na(1), one In(1), and one P(1) atom. In the second O site, O(7) is bonded in a 3-coordinate geometry to one Na(1), one In(1), and one P(1) atom. In the third O site, O(1) is bonded in a distorted trigonal planar geometry to one Na(1), one In(1), and one P(1) atom. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to one Na(1), one In(1), and one P(2) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one P(1), and one P(2) atom. In the sixth O site, O(4) is bonded in a bent 150 degrees geometry to one In(1) and one P(2) atom. In the seventh O site, O(5) is bonded in a distorted trigonal planar geometry to one Na(1), one In(1), and one P(2) atom.