K4Sb2O5 is Krennerite-derived structured and crystallizes in the orthorhombic Pnma space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(3) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to two equivalent O(3) and four equivalent O(2) atoms. In the third K site, K(3) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. In the fourth K site, K(4) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(3) atoms. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1) and two equivalent O(2) atoms. In the second Sb site, Sb(2) is bonded in a distorted trigonal non-coplanar geometry to one O(1) and two equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(3), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded to one K(1), one K(3), one K(4), two equivalent K(2), and one Sb(1) atom to form a mixture of distorted corner, face, and edge-sharing OK5Sb octahedra. The corner-sharing octahedral tilt angles range from 40-65°. In the third O site, O(3) is bonded to one K(1), one K(2), one K(3), two equivalent K(4), and one Sb(2) atom to form a mixture of distorted corner, face, and edge-sharing OK5Sb octahedra. The corner-sharing octahedral tilt angles range from 40-65°.
K4Sb2O5 is Krennerite-derived structured and crystallizes in the orthorhombic Pnma space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(3) atoms. Both K(1)-O(2) bond lengths are 2.79 Å. Both K(1)-O(3) bond lengths are 2.80 Å. In the second K site, K(2) is bonded in a 6-coordinate geometry to two equivalent O(3) and four equivalent O(2) atoms. Both K(2)-O(3) bond lengths are 2.88 Å. There are two shorter (2.67 Å) and two longer (2.88 Å) K(2)-O(2) bond lengths. In the third K site, K(3) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. The K(3)-O(1) bond length is 2.77 Å. Both K(3)-O(2) bond lengths are 2.79 Å. Both K(3)-O(3) bond lengths are 2.80 Å. In the fourth K site, K(4) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(3) atoms. Both K(4)-O(2) bond lengths are 2.90 Å. There are two shorter (2.65 Å) and two longer (2.91 Å) K(4)-O(3) bond lengths. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1) and two equivalent O(2) atoms. The Sb(1)-O(1) bond length is 2.02 Å. Both Sb(1)-O(2) bond lengths are 1.92 Å. In the second Sb site, Sb(2) is bonded in a distorted trigonal non-coplanar geometry to one O(1) and two equivalent O(3) atoms. The Sb(2)-O(1) bond length is 2.01 Å. Both Sb(2)-O(3) bond lengths are 1.92 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(3), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded to one K(1), one K(3), one K(4), two equivalent K(2), and one Sb(1) atom to form a mixture of distorted corner, face, and edge-sharing OK5Sb octahedra. The corner-sharing octahedral tilt angles range from 40-65°. In the third O site, O(3) is bonded to one K(1), one K(2), one K(3), two equivalent K(4), and one Sb(2) atom to form a mixture of distorted corner, face, and edge-sharing OK5Sb octahedra. The corner-sharing octahedral tilt angles range from 40-65°.