Materials Data on K2MgFe(SiO3)8 by Materials Project
K2MgFe(SiO3)8 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to twelve O atoms to form distorted KO12 cuboctahedra that share edges with six KO12 cuboctahedra and edges with twelve SiO4 tetrahedra. There are a spread of K–O bond distances ranging from 3.04–3.35 Å. In the second K site, K is bonded to twelve O atoms to form KO12 cuboctahedra that share edges with six KO12 cuboctahedra and edges with twelve SiO4 tetrahedra. There are a spread of K–O bond distances ranging from 3.04–3.26 Å. Mg is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Mg–O bond distances ranging from 1.95–2.30 Å. Fe is bonded to six O atoms to form distorted FeO6 octahedra that share corners with four SiO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.96–2.05 Å. There are eight inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with three SiO4 tetrahedra, and edges with three KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 44°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three SiO4 tetrahedra and edges with three KO12 cuboctahedra. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three SiO4 tetrahedra and edges with three KO12 cuboctahedra. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with three SiO4 tetrahedra, and edges with three KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the fifth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with three SiO4 tetrahedra, and edges with three KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 47°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the sixth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three SiO4 tetrahedra and edges with three KO12 cuboctahedra. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the seventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with three SiO4 tetrahedra, and edges with three KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 44°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the eighth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three SiO4 tetrahedra and edges with three KO12 cuboctahedra. There are a spread of Si–O bond distances ranging from 1.59–1.67 Å. There are twenty-four inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent K and two Si atoms. In the second O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent K and two Si atoms. In the third O site, O is bonded in a distorted bent 120 degrees geometry to two K and two Si atoms. In the fourth O site, O is bonded in a distorted bent 120 degrees geometry to two K and two Si atoms. In the fifth O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent K and two Si atoms. In the sixth O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent K and two Si atoms. In the seventh O site, O is bonded in a 2-coordinate geometry to two K and two Si atoms. In the eighth O site, O is bonded in a distorted bent 150 degrees geometry to two K and two Si atoms. In the ninth O site, O is bonded in a 2-coordinate geometry to two K and two Si atoms. In the tenth O site, O is bonded in a distorted bent 120 degrees geometry to two K and two Si atoms. In the eleventh O site, O is bonded in a 2-coordinate geometry to two K and two Si atoms. In the twelfth O site, O is bonded in a 2-coordinate geometry to two K and two Si atoms. In the thirteenth O site, O is bonded in a single-bond geometry to one Fe atom. In the fourteenth O site, O is bonded in a single-bond geometry to one Mg atom. In the fifteenth O site, O is bonded in a single-bond geometry to one Fe atom. In the sixteenth O site, O is bonded in a single-bond geometry to one Mg atom. In the seventeenth O site, O is bonded in a distorted bent 150 degrees geometry to one Fe and one Si atom. In the eighteenth O site, O is bonded in a distorted bent 150 degrees geometry to one Mg and one Si atom. In the nineteenth O site, O is bonded in a distorted bent 150 degrees geometry to one Mg and one Si atom. In the twentieth O site, O is bonded in a distorted bent 120 degrees geometry to one Fe and one Si atom. In the twenty-first O site, O is bonded in a distorted bent 120 degrees geometry to one Fe and one Si atom. In the twenty-second O site, O is bonded in a distorted bent 120 degrees geometry to one Mg and one Si atom. In the twenty-third O site, O is bonded in a distorted bent 150 degrees geometry to one Fe and one Si atom. In the twenty-fourth O site, O is bonded in a distorted bent 150 degrees geometry to one Mg and one Si atom.