K2FeH4(SO5)2 crystallizes in the triclinic P-1 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one O(5); two O(1,1); two O(2,2); two equivalent O(3); and two O(4,4) atoms. In the second K site, K(1) is bonded in a 9-coordinate geometry to one O(5); two equivalent O(1); two O(2,2); two O(3,3); and two O(4,4) atoms. In the third K site, K(1) is bonded in a 9-coordinate geometry to one O(5); two O(1,1); two O(2,2); two equivalent O(3); and two O(4,4) atoms. In the fourth K site, K(1) is bonded in a 9-coordinate geometry to one O(5); two equivalent O(1); two O(2,2); two O(3,3); and two O(4,4) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two O(1,1); two O(4,4); and two O(5,5) atoms to form FeO6 octahedra that share corners with four S(1,1,1,1)O4 tetrahedra. In the second Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with four S(1,1)O4 tetrahedra. In the third Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with four S(1,1)O4 tetrahedra. There are eight inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) atom. In the second H site, H(1) is bonded in a single-bond geometry to one O(5) atom. In the third H site, H(1) is bonded in a single-bond geometry to one O(5) atom. In the fourth H site, H(1) is bonded in a single-bond geometry to one O(5) atom. In the fifth H site, H(2) is bonded in a single-bond geometry to one O(5) atom. In the sixth H site, H(2) is bonded in a single-bond geometry to one O(5) atom. In the seventh H site, H(2) is bonded in a single-bond geometry to one O(5) atom. In the eighth H site, H(2) is bonded in a single-bond geometry to one O(5) atom. There are four inequivalent S sites. In the first S site, S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two Fe(1,1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-49°. In the second S site, S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two Fe(1,1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-48°. In the third S site, S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two Fe(1,1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-49°. In the fourth S site, S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two Fe(1,1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-49°. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(1), and one S(1) atom. In the second O site, O(1) is bonded in a 2-coordinate geometry to two K(1,1); one Fe(1); and one S(1) atom. In the third O site, O(1) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(1), and one S(1) atom. In the fourth O site, O(1) is bonded in a 2-coordinate geometry to two K(1,1); one Fe(1); and one S(1) atom. In the fifth O site, O(2) is bonded in a distorted single-bond geometry to two K(1,1) and one S(1) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to two K(1,1) and one S(1) atom. In the seventh O site, O(2) is bonded in a distorted single-bond geometry to two K(1,1) and one S(1) atom. In the eighth O site, O(2) is bonded in a distorted single-bond geometry to two K(1,1) and one S(1) atom. In the ninth O site, O(3) is bonded in a distorted single-bond geometry to two K(1,1) and one S(1) atom. In the tenth O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(1) and one S(1) atom. In the eleventh O site, O(3) is bonded in a distorted single-bond geometry to two K(1,1) and one S(1) atom. In the twelfth O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(1) and one S(1) atom. In the thirteenth O site, O(4) is bonded in a 4-coordinate geometry to two K(1,1); one Fe(1); and one S(1) atom. In the fourteenth O site, O(4) is bonded in a 4-coordinate geometry to two K(1,1); one Fe(1); and one S(1) atom. In the fifteenth O site, O(4) is bonded in a 4-coordinate geometry to two K(1,1); one Fe(1); and one S(1) atom. In the sixteenth O site, O(4) is bonded in a 4-coordinate geometry to two K(1,1); one Fe(1); and one S(1) atom. In the seventeenth O site, O(5) is bonded in a distorted water-like geometry to one K(1), one Fe(1), one H(1), and one H(2) atom. In the eighteenth O site, O(5) is bonded in a distorted water-like geometry to one K(1), one Fe(1), one H(1), and one H(2) atom. In the nineteenth O site, O(5) is bonded in a distorted water-like geometry to one K(1), one Fe(1), one H(1), and one H(2) atom. In the twentieth O site, O(5) is bonded in a distorted water-like geometry to one K(1), one Fe(1), one H(1), and one H(2) atom.
K2FeH4(SO5)2 crystallizes in the triclinic P-1 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one O(5); two O(1,1); two O(2,2); two equivalent O(3); and two O(4,4) atoms. The K(1)-O(5) bond length is 2.89 Å. There is one shorter (2.89 Å) and one longer (3.29 Å) K(1)-O(1,1) bond length. There is one shorter (2.85 Å) and one longer (3.07 Å) K(1)-O(2,2) bond length. There is one shorter (2.84 Å) and one longer (3.10 Å) K(1)-O(3) bond length. There is one shorter (2.85 Å) and one longer (2.86 Å) K(1)-O(4,4) bond length. In the second K site, K(1) is bonded in a 9-coordinate geometry to one O(5); two equivalent O(1); two O(2,2); two O(3,3); and two O(4,4) atoms. The K(1)-O(5) bond length is 2.89 Å. There is one shorter (2.89 Å) and one longer (3.29 Å) K(1)-O(1) bond length. There is one shorter (2.85 Å) and one longer (3.07 Å) K(1)-O(2,2) bond length. There is one shorter (2.84 Å) and one longer (3.10 Å) K(1)-O(3,3) bond length. There is one shorter (2.85 Å) and one longer (2.86 Å) K(1)-O(4,4) bond length. In the third K site, K(1) is bonded in a 9-coordinate geometry to one O(5); two O(1,1); two O(2,2); two equivalent O(3); and two O(4,4) atoms. The K(1)-O(5) bond length is 2.89 Å. There is one shorter (2.89 Å) and one longer (3.29 Å) K(1)-O(1,1) bond length. There is one shorter (2.85 Å) and one longer (3.08 Å) K(1)-O(2,2) bond length. There is one shorter (2.84 Å) and one longer (3.10 Å) K(1)-O(3) bond length. There is one shorter (2.85 Å) and one longer (2.86 Å) K(1)-O(4,4) bond length. In the fourth K site, K(1) is bonded in a 9-coordinate geometry to one O(5); two equivalent O(1); two O(2,2); two O(3,3); and two O(4,4) atoms. The K(1)-O(5) bond length is 2.89 Å. There is one shorter (2.89 Å) and one longer (3.29 Å) K(1)-O(1) bond length. There is one shorter (2.85 Å) and one longer (3.08 Å) K(1)-O(2,2) bond length. There is one shorter (2.84 Å) and one longer (3.10 Å) K(1)-O(3,3) bond length. There is one shorter (2.85 Å) and one longer (2.86 Å) K(1)-O(4,4) bond length. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two O(1,1); two O(4,4); and two O(5,5) atoms to form FeO6 octahedra that share corners with four S(1,1,1,1)O4 tetrahedra. Both Fe(1)-O(1,1) bond lengths are 2.19 Å. Both Fe(1)-O(4,4) bond lengths are 2.11 Å. There is one shorter (2.17 Å) and one longer (2.18 Å) Fe(1)-O(5,5) bond length. In the second Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with four S(1,1)O4 tetrahedra. Both Fe(1)-O(1) bond lengths are 2.19 Å. Both Fe(1)-O(4) bond lengths are 2.11 Å. Both Fe(1)-O(5) bond lengths are 2.18 Å. In the third Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with four S(1,1)O4 tetrahedra. Both Fe(1)-O(1) bond lengths are 2.19 Å. Both Fe(1)-O(4) bond lengths are 2.11 Å. Both Fe(1)-O(5) bond lengths are 2.18 Å. There are eight inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.98 Å. In the second H site, H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.98 Å. In the third H site, H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.98 Å. In the fourth H site, H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.98 Å. In the fifth H site, H(2) is bonded in a single-bond geometry to one O(5) atom. The H(2)-O(5) bond length is 0.99 Å. In the sixth H site, H(2) is bonded in a single-bond geometry to one O(5) atom. The H(2)-O(5) bond length is 0.99 Å. In the seventh H site, H(2) is bonded in a single-bond geometry to one O(5) atom. The H(2)-O(5) bond length is 0.99 Å. In the eighth H site, H(2) is bonded in a single-bond geometry to one O(5) atom. The H(2)-O(5) bond length is 0.99 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two Fe(1,1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-49°. The S(1)-O(1) bond length is 1.50 Å. The S(1)-O(2) bond length is 1.47 Å. The S(1)-O(3) bond length is 1.50 Å. The S(1)-O(4) bond length is 1.52 Å. In the second S site, S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two Fe(1,1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-48°. The S(1)-O(1) bond length is 1.50 Å. The S(1)-O(2) bond length is 1.47 Å. The S(1)-O(3) bond length is 1.50 Å. The S(1)-O(4) bond length is 1.52 Å. In the third S site, S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two Fe(1,1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-49°. The S(1)-O(1) bond length is 1.50 Å. The S(1)-O(2) bond length is 1.47 Å. The S(1)-O(3) bond length is 1.50 Å. The S(1)-O(4) bond length is 1.52 Å. In the fourth S site, S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with two Fe(1,1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-49°. The S(1)-O(1) bond length is 1.50 Å. The S(1)-O(2) bond length is 1.47 Å. The S(1)-O(3) bond length is 1.50 Å. The S(1)-O(4) bond length is 1.52 Å. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(1), and one S(1) atom. In the second O site, O(1) is bonded in a 2-coordinate geometry to two K(1,1); one Fe(1); and one S(1) atom. In the third O site, O(1) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(1), and one S(1) atom. In the fourth O site, O(1) is bonded in a 2-coordinate geometry to two K(1,1); one Fe(1); and one S(1) atom. In the fifth O site, O(2) is bonded in a distorted single-bond geometry to two K(1,1) and one S(1) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to two K(1,1) and one S(1) atom. In the seventh O site, O(2) is bonded in a distorted single-bond geometry to two K(1,1) and one S(1) atom. In the eighth O site, O(2) is bonded in a distorted single-bond geometry to two K(1,1) and one S(1) atom. In the ninth O site, O(3) is bonded in a distorted single-bond geometry to two K(1,1) and one S(1) atom. In the tenth O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(1) and one S(1) atom. In the eleventh O site, O(3) is bonded in a distorted single-bond geometry to two K(1,1) and one S(1) atom. In the twelfth O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(1) and one S(1) atom. In the thirteenth O site, O(4) is bonded in a 4-coordinate geometry to two K(1,1); one Fe(1); and one S(1) atom. In the fourteenth O site, O(4) is bonded in a 4-coordinate geometry to two K(1,1); one Fe(1); and one S(1) atom. In the fifteenth O site, O(4) is bonded in a 4-coordinate geometry to two K(1,1); one Fe(1); and one S(1) atom. In the sixteenth O site, O(4) is bonded in a 4-coordinate geometry to two K(1,1); one Fe(1); and one S(1) atom. In the seventeenth O site, O(5) is bonded in a distorted water-like geometry to one K(1), one Fe(1), one H(1), and one H(2) atom. In the eighteenth O site, O(5) is bonded in a distorted water-like geometry to one K(1), one Fe(1), one H(1), and one H(2) atom. In the nineteenth O site, O(5) is bonded in a distorted water-like geometry to one K(1), one Fe(1), one H(1), and one H(2) atom. In the twentieth O site, O(5) is bonded in a distorted water-like geometry to one K(1), one Fe(1), one H(1), and one H(2) atom.