K2AsH13O10 crystallizes in the monoclinic Cc space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to one O(10), one O(3), one O(6), one O(7), one O(8), and one O(9) atom to form distorted KO6 pentagonal pyramids that share  a cornercorner with one As(1)O4 tetrahedra. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(5), one O(6), one O(7), and one O(9) atom. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share  a cornercorner with one K(1)O6 pentagonal pyramid. There are thirteen inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. In the second H site, H(2) is bonded in a distorted single-bond geometry to one O(4) and one O(5) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(5) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(6) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(6) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(7) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(7) atom. In the eighth H site, H(8) is bonded in a distorted single-bond geometry to one O(8) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(8) atom. In the tenth H site, H(10) is bonded in a single-bond geometry to one O(9) atom. In the eleventh H site, H(11) is bonded in a single-bond geometry to one O(9) atom. In the twelfth H site, H(12) is bonded in a single-bond geometry to one O(10) atom. In the thirteenth H site, H(13) is bonded in a single-bond geometry to one O(10) atom. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one As(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one K(2) and one As(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one K(1), one K(2), one As(1), and one H(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one As(1) and one H(2) atom. In the fifth O site, O(5) is bonded in a water-like geometry to one K(2), one H(2), and one H(3) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to one K(1), one K(2), one H(4), and one H(5) atom. In the seventh O site, O(7) is bonded in a water-like geometry to one K(1), one K(2), one H(6), and one H(7) atom. In the eighth O site, O(8) is bonded in a distorted water-like geometry to one K(1), one H(8), and one H(9) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one K(1), one K(2), one H(10), and one H(11) atom. In the tenth O site, O(10) is bonded in a water-like geometry to one K(1), one H(12), and one H(13) atom.
K2AsH13O10 crystallizes in the monoclinic Cc space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to one O(10), one O(3), one O(6), one O(7), one O(8), and one O(9) atom to form distorted KO6 pentagonal pyramids that share  a cornercorner with one As(1)O4 tetrahedra. The K(1)-O(10) bond length is 2.82 Å. The K(1)-O(3) bond length is 2.99 Å. The K(1)-O(6) bond length is 2.74 Å. The K(1)-O(7) bond length is 2.80 Å. The K(1)-O(8) bond length is 2.75 Å. The K(1)-O(9) bond length is 2.84 Å. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(5), one O(6), one O(7), and one O(9) atom. The K(2)-O(2) bond length is 2.70 Å. The K(2)-O(3) bond length is 3.07 Å. The K(2)-O(5) bond length is 2.86 Å. The K(2)-O(6) bond length is 2.69 Å. The K(2)-O(7) bond length is 2.97 Å. The K(2)-O(9) bond length is 2.80 Å. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share  a cornercorner with one K(1)O6 pentagonal pyramid. The As(1)-O(1) bond length is 1.72 Å. The As(1)-O(2) bond length is 1.70 Å. The As(1)-O(3) bond length is 1.80 Å. The As(1)-O(4) bond length is 1.71 Å. There are thirteen inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. The H(1)-O(3) bond length is 1.01 Å. In the second H site, H(2) is bonded in a distorted single-bond geometry to one O(4) and one O(5) atom. The H(2)-O(4) bond length is 1.66 Å. The H(2)-O(5) bond length is 1.01 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(5) atom. The H(3)-O(5) bond length is 0.99 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(6) atom. The H(4)-O(6) bond length is 0.99 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(6) atom. The H(5)-O(6) bond length is 0.99 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(7) atom. The H(6)-O(7) bond length is 1.00 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(7) atom. The H(7)-O(7) bond length is 1.00 Å. In the eighth H site, H(8) is bonded in a distorted single-bond geometry to one O(8) atom. The H(8)-O(8) bond length is 1.01 Å. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(8) atom. The H(9)-O(8) bond length is 0.98 Å. In the tenth H site, H(10) is bonded in a single-bond geometry to one O(9) atom. The H(10)-O(9) bond length is 0.99 Å. In the eleventh H site, H(11) is bonded in a single-bond geometry to one O(9) atom. The H(11)-O(9) bond length is 0.98 Å. In the twelfth H site, H(12) is bonded in a single-bond geometry to one O(10) atom. The H(12)-O(10) bond length is 0.99 Å. In the thirteenth H site, H(13) is bonded in a single-bond geometry to one O(10) atom. The H(13)-O(10) bond length is 0.99 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one As(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one K(2) and one As(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one K(1), one K(2), one As(1), and one H(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one As(1) and one H(2) atom. In the fifth O site, O(5) is bonded in a water-like geometry to one K(2), one H(2), and one H(3) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to one K(1), one K(2), one H(4), and one H(5) atom. In the seventh O site, O(7) is bonded in a water-like geometry to one K(1), one K(2), one H(6), and one H(7) atom. In the eighth O site, O(8) is bonded in a distorted water-like geometry to one K(1), one H(8), and one H(9) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one K(1), one K(2), one H(10), and one H(11) atom. In the tenth O site, O(10) is bonded in a water-like geometry to one K(1), one H(12), and one H(13) atom.