Materials Data on K2Fe9H18S6O43 by Materials Project
(K2Fe9H18(SO7)6)2O2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional and consists of two water molecules and one K2Fe9H18(SO7)6 framework. In the K2Fe9H18(SO7)6 framework, K is bonded to twelve O atoms to form KO12 cuboctahedra that share corners with six SO4 tetrahedra and faces with six FeO6 octahedra. There are a spread of K–O bond distances ranging from 2.90–3.05 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four FeO6 octahedra, corners with two SO4 tetrahedra, and a faceface with one KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 45–46°. There are a spread of Fe–O bond distances ranging from 2.00–2.08 Å. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four FeO6 octahedra, corners with two equivalent SO4 tetrahedra, and faces with two equivalent KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 46–47°. There are four shorter (2.02 Å) and two longer (2.06 Å) Fe–O bond lengths. In the third Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four equivalent FeO6 octahedra, corners with two equivalent SO4 tetrahedra, and faces with two equivalent KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 46°. There are four shorter (2.01 Å) and two longer (2.06 Å) Fe–O bond lengths. In the fourth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four FeO6 octahedra, corners with two SO4 tetrahedra, and a faceface with one KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 45–46°. There are a spread of Fe–O bond distances ranging from 2.01–2.08 Å. There are six inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the second H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the third H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the fourth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the fifth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the sixth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. There are three inequivalent S sites. In the first S site, S is bonded to four O atoms to form SO4 tetrahedra that share corners with two equivalent KO12 cuboctahedra and corners with three FeO6 octahedra. The corner-sharing octahedra tilt angles range from 48–50°. There are a spread of S–O bond distances ranging from 1.47–1.50 Å. In the second S site, S is bonded to four O atoms to form SO4 tetrahedra that share corners with three equivalent KO12 cuboctahedra and corners with three FeO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There is one shorter (1.47 Å) and three longer (1.50 Å) S–O bond length. In the third S site, S is bonded to four O atoms to form SO4 tetrahedra that share a cornercorner with one KO12 cuboctahedra and corners with three FeO6 octahedra. The corner-sharing octahedra tilt angles range from 49–50°. There is one shorter (1.47 Å) and three longer (1.50 Å) S–O bond length. There are fifteen inequivalent O sites. In the first O site, O is bonded in a 2-coordinate geometry to one K, one Fe, and one S atom. In the second O site, O is bonded in a 2-coordinate geometry to one K, one Fe, and one S atom. In the third O site, O is bonded in a bent 120 degrees geometry to one Fe and one S atom. In the fourth O site, O is bonded in a distorted bent 120 degrees geometry to one Fe and one S atom. In the fifth O site, O is bonded in a 2-coordinate geometry to one K, one Fe, and one S atom. In the sixth O site, O is bonded in a 2-coordinate geometry to one K, one Fe, and one S atom. In the seventh O site, O is bonded in a distorted single-bond geometry to one K, two Fe, and one H atom. In the eighth O site, O is bonded in a distorted single-bond geometry to one K, two Fe, and one H atom. In the ninth O site, O is bonded in a distorted single-bond geometry to two Fe and one H atom. In the tenth O site, O is bonded in a distorted single-bond geometry to two equivalent Fe and one H atom. In the eleventh O site, O is bonded in a distorted single-bond geometry to one K, two equivalent Fe, and one H atom. In the twelfth O site, O is bonded in a distorted single-bond geometry to one K, two equivalent Fe, and one H atom. In the thirteenth O site, O is bonded in a single-bond geometry to one S atom. In the fourteenth O site, O is bonded in a single-bond geometry to one S atom. In the fifteenth O site, O is bonded in a single-bond geometry to one S atom.