KFeH5(SO5)2 crystallizes in the triclinic P1 space group. K(1) is bonded in a 5-coordinate geometry to one O(4), one O(5), one O(6), one O(7), and one O(9) atom. Fe(1) is bonded in a distorted square pyramidal geometry to one O(1), one O(10), one O(4), one O(5), and one O(8) atom. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(10) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(9) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(1) atom. In the fourth H site, H(4) is bonded in a distorted single-bond geometry to one O(10) and one O(2) atom. In the fifth H site, H(5) is bonded in a linear geometry to one O(1) and one O(6) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded in a trigonal non-coplanar geometry to one O(2), one O(4), and one O(8) atom. In the second S site, S(2) is bonded in a trigonal non-coplanar geometry to one O(3), 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 distorted trigonal planar geometry to one Fe(1), one H(3), and one H(5) atom. In the second O site, O(2) is bonded in a water-like geometry to one H(4) and one S(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to one S(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one K(1), one Fe(1), and one S(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one K(1) and one Fe(1) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one K(1), one H(5), and one O(7) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one K(1), one S(2), and one O(6) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Fe(1) and one S(1) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one K(1), one H(2), and one S(2) atom. In the tenth O site, O(10) is bonded in a distorted water-like geometry to one Fe(1), one H(1), and one H(4) atom.
KFeH5(SO5)2 crystallizes in the triclinic P1 space group. K(1) is bonded in a 5-coordinate geometry to one O(4), one O(5), one O(6), one O(7), and one O(9) atom. The K(1)-O(4) bond length is 2.96 Å. The K(1)-O(5) bond length is 2.87 Å. The K(1)-O(6) bond length is 2.89 Å. The K(1)-O(7) bond length is 2.76 Å. The K(1)-O(9) bond length is 3.02 Å. Fe(1) is bonded in a distorted square pyramidal geometry to one O(1), one O(10), one O(4), one O(5), and one O(8) atom. The Fe(1)-O(1) bond length is 1.95 Å. The Fe(1)-O(10) bond length is 2.26 Å. The Fe(1)-O(4) bond length is 2.18 Å. The Fe(1)-O(5) bond length is 1.74 Å. The Fe(1)-O(8) bond length is 2.00 Å. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(10) atom. The H(1)-O(10) bond length is 0.98 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(9) atom. The H(2)-O(9) bond length is 0.99 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(1) atom. The H(3)-O(1) bond length is 0.98 Å. In the fourth H site, H(4) is bonded in a distorted single-bond geometry to one O(10) and one O(2) atom. The H(4)-O(10) bond length is 1.00 Å. The H(4)-O(2) bond length is 1.66 Å. In the fifth H site, H(5) is bonded in a linear geometry to one O(1) and one O(6) atom. The H(5)-O(1) bond length is 1.49 Å. The H(5)-O(6) bond length is 1.06 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded in a trigonal non-coplanar geometry to one O(2), one O(4), and one O(8) atom. The S(1)-O(2) bond length is 1.50 Å. The S(1)-O(4) bond length is 1.52 Å. The S(1)-O(8) bond length is 1.53 Å. In the second S site, S(2) is bonded in a trigonal non-coplanar geometry to one O(3), one O(7), and one O(9) atom. The S(2)-O(3) bond length is 1.45 Å. The S(2)-O(7) bond length is 1.75 Å. The S(2)-O(9) bond length is 1.64 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Fe(1), one H(3), and one H(5) atom. In the second O site, O(2) is bonded in a water-like geometry to one H(4) and one S(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to one S(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one K(1), one Fe(1), and one S(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one K(1) and one Fe(1) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one K(1), one H(5), and one O(7) atom. The O(6)-O(7) bond length is 1.47 Å. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one K(1), one S(2), and one O(6) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Fe(1) and one S(1) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one K(1), one H(2), and one S(2) atom. In the tenth O site, O(10) is bonded in a distorted water-like geometry to one Fe(1), one H(1), and one H(4) atom.