Cs2K2TeO5 crystallizes in the tetragonal P4_2/mnm space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted CsO6 octahedra that share corners with six equivalent Te(1)O5 trigonal bipyramids and  an edgeedge with one Cs(1)O6 octahedra. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. K(1) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(1), and three equivalent O(2) atoms. Te(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form TeO5 trigonal bipyramids that share corners with six equivalent Cs(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-45°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Cs(1), two equivalent Cs(2), two equivalent K(1), and one Te(1) atom. In the second O site, O(2) is bonded in a 7-coordinate geometry to one Cs(1), two equivalent Cs(2), three equivalent K(1), and one Te(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to two equivalent Cs(1), two equivalent K(1), and one Te(1) atom.
Cs2K2TeO5 crystallizes in the tetragonal P4_2/mnm space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted CsO6 octahedra that share corners with six equivalent Te(1)O5 trigonal bipyramids and  an edgeedge with one Cs(1)O6 octahedra. Both Cs(1)-O(1) bond lengths are 3.21 Å. Both Cs(1)-O(2) bond lengths are 2.91 Å. Both Cs(1)-O(3) bond lengths are 3.08 Å. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. All Cs(2)-O(1) bond lengths are 3.25 Å. All Cs(2)-O(2) bond lengths are 3.47 Å. K(1) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(1), and three equivalent O(2) atoms. The K(1)-O(3) bond length is 2.81 Å. Both K(1)-O(1) bond lengths are 2.76 Å. There is one shorter (2.72 Å) and two longer (2.90 Å) K(1)-O(2) bond lengths. Te(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form TeO5 trigonal bipyramids that share corners with six equivalent Cs(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-45°. The Te(1)-O(3) bond length is 1.90 Å. Both Te(1)-O(1) bond lengths are 1.92 Å. Both Te(1)-O(2) bond lengths are 1.96 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Cs(1), two equivalent Cs(2), two equivalent K(1), and one Te(1) atom. In the second O site, O(2) is bonded in a 7-coordinate geometry to one Cs(1), two equivalent Cs(2), three equivalent K(1), and one Te(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to two equivalent Cs(1), two equivalent K(1), and one Te(1) atom.