K2W2O5 crystallizes in the triclinic P1 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a distorted single-bond geometry to one W(4), one O(2), two equivalent O(5), and two equivalent O(7) atoms. In the second K site, K(2) is bonded in a distorted single-bond geometry to one W(4), one O(3), two equivalent O(6), and two equivalent O(8) atoms. In the third K site, K(3) is bonded in a distorted linear geometry to one W(4), one O(10), one O(3), two equivalent O(5), and two equivalent O(7) atoms. In the fourth K site, K(4) is bonded in a distorted linear geometry to one W(4), one O(10), one O(2), two equivalent O(6), and two equivalent O(8) atoms. There are four inequivalent W sites. In the first W site, W(1) is bonded in a distorted square co-planar geometry to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(8) atom. In the second W site, W(2) is bonded in a distorted square co-planar geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the third W site, W(3) is bonded in a distorted water-like geometry to one O(10), one O(5), one O(6), one O(8), and one O(9) atom. In the fourth W site, W(4) is bonded in a 9-coordinate geometry to one K(1), one K(2), one K(3), one K(4), one O(10), one O(5), one O(6), one O(7), and one O(9) atom. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one W(1) and one W(2) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one K(4), one W(1), and one W(2) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one K(2), one K(3), one W(1), and one W(2) atom. In the fourth O site, O(4) is bonded in a linear geometry to one W(1) and one W(2) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent K(3), one W(3), and one W(4) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to two equivalent K(2), two equivalent K(4), one W(3), and one W(4) atom. In the seventh O site, O(7) is bonded in a 7-coordinate geometry to two equivalent K(1), two equivalent K(3), one W(1), one W(4), and one O(9) atom. In the eighth O site, O(8) is bonded in a 7-coordinate geometry to two equivalent K(2), two equivalent K(4), one W(1), one W(3), and one O(9) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to one W(3), one W(4), one O(7), and one O(8) atom. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to one K(3), one K(4), one W(3), and one W(4) atom.
K2W2O5 crystallizes in the triclinic P1 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a distorted single-bond geometry to one W(4), one O(2), two equivalent O(5), and two equivalent O(7) atoms. The K(1)-W(4) bond length is 2.91 Å. The K(1)-O(2) bond length is 1.87 Å. There is one shorter (2.81 Å) and one longer (3.03 Å) K(1)-O(5) bond length. There is one shorter (2.71 Å) and one longer (3.12 Å) K(1)-O(7) bond length. In the second K site, K(2) is bonded in a distorted single-bond geometry to one W(4), one O(3), two equivalent O(6), and two equivalent O(8) atoms. The K(2)-W(4) bond length is 2.84 Å. The K(2)-O(3) bond length is 1.88 Å. There is one shorter (2.82 Å) and one longer (3.02 Å) K(2)-O(6) bond length. There is one shorter (2.64 Å) and one longer (3.19 Å) K(2)-O(8) bond length. In the third K site, K(3) is bonded in a distorted linear geometry to one W(4), one O(10), one O(3), two equivalent O(5), and two equivalent O(7) atoms. The K(3)-W(4) bond length is 2.98 Å. The K(3)-O(10) bond length is 2.08 Å. The K(3)-O(3) bond length is 2.04 Å. There is one shorter (2.85 Å) and one longer (2.98 Å) K(3)-O(5) bond length. There is one shorter (2.87 Å) and one longer (3.00 Å) K(3)-O(7) bond length. In the fourth K site, K(4) is bonded in a distorted linear geometry to one W(4), one O(10), one O(2), two equivalent O(6), and two equivalent O(8) atoms. The K(4)-W(4) bond length is 2.93 Å. The K(4)-O(10) bond length is 2.02 Å. The K(4)-O(2) bond length is 2.04 Å. There is one shorter (2.90 Å) and one longer (2.93 Å) K(4)-O(6) bond length. There is one shorter (2.87 Å) and one longer (3.01 Å) K(4)-O(8) bond length. There are four inequivalent W sites. In the first W site, W(1) is bonded in a distorted square co-planar geometry to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(8) atom. The W(1)-O(1) bond length is 2.14 Å. The W(1)-O(2) bond length is 1.95 Å. The W(1)-O(3) bond length is 1.95 Å. The W(1)-O(4) bond length is 2.14 Å. The W(1)-O(7) bond length is 2.80 Å. The W(1)-O(8) bond length is 2.79 Å. In the second W site, W(2) is bonded in a distorted square co-planar geometry to one O(1), one O(2), one O(3), and one O(4) atom. The W(2)-O(1) bond length is 1.98 Å. The W(2)-O(2) bond length is 2.20 Å. The W(2)-O(3) bond length is 2.19 Å. The W(2)-O(4) bond length is 1.96 Å. In the third W site, W(3) is bonded in a distorted water-like geometry to one O(10), one O(5), one O(6), one O(8), and one O(9) atom. The W(3)-O(10) bond length is 1.89 Å. The W(3)-O(5) bond length is 2.88 Å. The W(3)-O(6) bond length is 2.83 Å. The W(3)-O(8) bond length is 2.63 Å. The W(3)-O(9) bond length is 1.90 Å. In the fourth W site, W(4) is bonded in a 9-coordinate geometry to one K(1), one K(2), one K(3), one K(4), one O(10), one O(5), one O(6), one O(7), and one O(9) atom. The W(4)-O(10) bond length is 2.23 Å. The W(4)-O(5) bond length is 2.67 Å. The W(4)-O(6) bond length is 2.71 Å. The W(4)-O(7) bond length is 2.77 Å. The W(4)-O(9) bond length is 2.33 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one W(1) and one W(2) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one K(4), one W(1), and one W(2) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one K(2), one K(3), one W(1), and one W(2) atom. In the fourth O site, O(4) is bonded in a linear geometry to one W(1) and one W(2) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent K(3), one W(3), and one W(4) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to two equivalent K(2), two equivalent K(4), one W(3), and one W(4) atom. In the seventh O site, O(7) is bonded in a 7-coordinate geometry to two equivalent K(1), two equivalent K(3), one W(1), one W(4), and one O(9) atom. The O(7)-O(9) bond length is 1.94 Å. In the eighth O site, O(8) is bonded in a 7-coordinate geometry to two equivalent K(2), two equivalent K(4), one W(1), one W(3), and one O(9) atom. The O(8)-O(9) bond length is 1.92 Å. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to one W(3), one W(4), one O(7), and one O(8) atom. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to one K(3), one K(4), one W(3), and one W(4) atom.