K2InP2S7 crystallizes in the monoclinic C2/m space group. K(1) is bonded in a 8-coordinate geometry to one S(2), one S(5), two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms. In(1) is bonded to two equivalent S(1), two equivalent S(3), and two equivalent S(5) atoms to form InS6 octahedra that share  an edgeedge with one In(1)S6 octahedra and edges with two equivalent P(2)S4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded in a distorted trigonal non-coplanar geometry to one P(1), one S(2), and two equivalent S(3) atoms. In the second P site, P(2) is bonded to one S(4), one S(5), and two equivalent S(1) atoms to form PS4 tetrahedra that share edges with two equivalent In(1)S6 octahedra. There are five inequivalent S sites. In the first S site, S(5) is bonded in a 3-coordinate geometry to two equivalent K(1), two equivalent In(1), and one P(2) atom. In the second S site, S(1) is bonded in a 4-coordinate geometry to two equivalent K(1), one In(1), and one P(2) atom. In the third S site, S(2) is bonded in a distorted single-bond geometry to two equivalent K(1) and one P(1) atom. In the fourth S site, S(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(1), one In(1), and one P(1) atom. In the fifth S site, S(4) is bonded to four equivalent K(1) and one P(2) atom to form distorted edge-sharing SK4P square pyramids.
K2InP2S7 crystallizes in the monoclinic C2/m space group. K(1) is bonded in a 8-coordinate geometry to one S(2), one S(5), two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms. The K(1)-S(2) bond length is 3.47 Å. The K(1)-S(5) bond length is 3.74 Å. There is one shorter (3.34 Å) and one longer (3.38 Å) K(1)-S(1) bond length. There is one shorter (3.44 Å) and one longer (3.54 Å) K(1)-S(3) bond length. There is one shorter (3.36 Å) and one longer (3.54 Å) K(1)-S(4) bond length. In(1) is bonded to two equivalent S(1), two equivalent S(3), and two equivalent S(5) atoms to form InS6 octahedra that share  an edgeedge with one In(1)S6 octahedra and edges with two equivalent P(2)S4 tetrahedra. Both In(1)-S(1) bond lengths are 2.59 Å. Both In(1)-S(3) bond lengths are 2.60 Å. Both In(1)-S(5) bond lengths are 2.80 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded in a distorted trigonal non-coplanar geometry to one P(1), one S(2), and two equivalent S(3) atoms. The P(1)-P(1) bond length is 2.32 Å. The P(1)-S(2) bond length is 1.99 Å. Both P(1)-S(3) bond lengths are 2.07 Å. In the second P site, P(2) is bonded to one S(4), one S(5), and two equivalent S(1) atoms to form PS4 tetrahedra that share edges with two equivalent In(1)S6 octahedra. The P(2)-S(4) bond length is 2.01 Å. The P(2)-S(5) bond length is 2.11 Å. Both P(2)-S(1) bond lengths are 2.07 Å. There are five inequivalent S sites. In the first S site, S(5) is bonded in a 3-coordinate geometry to two equivalent K(1), two equivalent In(1), and one P(2) atom. In the second S site, S(1) is bonded in a 4-coordinate geometry to two equivalent K(1), one In(1), and one P(2) atom. In the third S site, S(2) is bonded in a distorted single-bond geometry to two equivalent K(1) and one P(1) atom. In the fourth S site, S(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(1), one In(1), and one P(1) atom. In the fifth S site, S(4) is bonded to four equivalent K(1) and one P(2) atom to form distorted edge-sharing SK4P square pyramids.