KInP2O7 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(5), two equivalent O(6), and two equivalent O(7) atoms. In(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 InO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) 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 and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 21-55°. In the second P site, P(2) is bonded to one O(1), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent In(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 20-52°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a distorted trigonal planar geometry to one K(1), one In(1), and one P(1) atom. In the second O site, O(6) is bonded in a 4-coordinate geometry to two equivalent K(1), one In(1), and one P(2) atom. In the third O site, O(7) is bonded in a 4-coordinate geometry to two equivalent K(1), one In(1), and one P(2) atom. In the fourth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one K(1), one In(1), and one P(2) atom. In the fifth O site, O(2) is bonded in a 2-coordinate geometry to one K(1), one In(1), and one P(1) atom. In the sixth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one K(1), one In(1), and one P(1) atom. In the seventh O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom.
KInP2O7 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(5), two equivalent O(6), and two equivalent O(7) atoms. The K(1)-O(1) bond length is 3.24 Å. The K(1)-O(2) bond length is 3.15 Å. The K(1)-O(3) bond length is 3.29 Å. The K(1)-O(5) bond length is 2.82 Å. There is one shorter (2.78 Å) and one longer (3.08 Å) K(1)-O(6) bond length. There is one shorter (2.78 Å) and one longer (2.96 Å) K(1)-O(7) bond length. In(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 InO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. The In(1)-O(1) bond length is 2.13 Å. The In(1)-O(2) bond length is 2.15 Å. The In(1)-O(3) bond length is 2.18 Å. The In(1)-O(5) bond length is 2.17 Å. The In(1)-O(6) bond length is 2.18 Å. The In(1)-O(7) bond length is 2.19 Å. There are two inequivalent P sites. In the first P site, P(1) 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 and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 21-55°. The P(1)-O(2) bond length is 1.53 Å. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(4) bond length is 1.64 Å. The P(1)-O(5) bond length is 1.54 Å. In the second P site, P(2) is bonded to one O(1), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent In(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 20-52°. The P(2)-O(1) bond length is 1.51 Å. The P(2)-O(4) bond length is 1.63 Å. The P(2)-O(6) bond length is 1.54 Å. The P(2)-O(7) bond length is 1.54 Å. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a distorted trigonal planar geometry to one K(1), one In(1), and one P(1) atom. In the second O site, O(6) is bonded in a 4-coordinate geometry to two equivalent K(1), one In(1), and one P(2) atom. In the third O site, O(7) is bonded in a 4-coordinate geometry to two equivalent K(1), one In(1), and one P(2) atom. In the fourth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one K(1), one In(1), and one P(2) atom. In the fifth O site, O(2) is bonded in a 2-coordinate geometry to one K(1), one In(1), and one P(1) atom. In the sixth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one K(1), one In(1), and one P(1) atom. In the seventh O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom.