K4W2OCl10 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to four equivalent Cl(2) and eight equivalent Cl(1) atoms to form KCl12 cuboctahedra that share corners with four equivalent K(1)Cl12 cuboctahedra, faces with four equivalent K(1)Cl12 cuboctahedra, and faces with four equivalent W(1)Cl5O octahedra. In the second K site, K(2) is bonded in a body-centered cubic geometry to eight equivalent Cl(1) atoms. W(1) is bonded to one O(1), one Cl(2), and four equivalent Cl(1) atoms to form WCl5O octahedra that share  a cornercorner with one W(1)Cl5O octahedra and faces with four equivalent K(1)Cl12 cuboctahedra. The corner-sharing octahedra are not tilted. O(1) is bonded in a linear geometry to two equivalent W(1) atoms. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to two equivalent K(1), two equivalent K(2), and one W(1) atom to form a mixture of distorted corner, edge, and face-sharing ClK4W square pyramids. In the second Cl site, Cl(2) is bonded in a distorted single-bond geometry to four equivalent K(1) and one W(1) atom.
K4W2OCl10 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to four equivalent Cl(2) and eight equivalent Cl(1) atoms to form KCl12 cuboctahedra that share corners with four equivalent K(1)Cl12 cuboctahedra, faces with four equivalent K(1)Cl12 cuboctahedra, and faces with four equivalent W(1)Cl5O octahedra. All K(1)-Cl(2) bond lengths are 3.68 Å. All K(1)-Cl(1) bond lengths are 3.60 Å. In the second K site, K(2) is bonded in a body-centered cubic geometry to eight equivalent Cl(1) atoms. All K(2)-Cl(1) bond lengths are 3.29 Å. W(1) is bonded to one O(1), one Cl(2), and four equivalent Cl(1) atoms to form WCl5O octahedra that share  a cornercorner with one W(1)Cl5O octahedra and faces with four equivalent K(1)Cl12 cuboctahedra. The corner-sharing octahedra are not tilted. The W(1)-O(1) bond length is 1.92 Å. The W(1)-Cl(2) bond length is 2.44 Å. All W(1)-Cl(1) bond lengths are 2.47 Å. O(1) is bonded in a linear geometry to two equivalent W(1) atoms. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to two equivalent K(1), two equivalent K(2), and one W(1) atom to form a mixture of distorted corner, edge, and face-sharing ClK4W square pyramids. In the second Cl site, Cl(2) is bonded in a distorted single-bond geometry to four equivalent K(1) and one W(1) atom.