Materials Data on CsAlFe3(SiO4)3 by Materials Project

Abstract

CsFe3Al(SiO4)3 crystallizes in the triclinic P1 space group. The structure is three-dimensional. Cs1+ is bonded to twelve O2- atoms to form distorted CsO12 cuboctahedra that share edges with six equivalent CsO12 cuboctahedra, edges with three equivalent AlO4 tetrahedra, and edges with nine SiO4 tetrahedra. There are a spread of Cs–O bond distances ranging from 3.10–3.55 Å. There are three inequivalent Fe+2.67+ sites. In the first Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.04–2.29 Å. In the second Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–2.20 Å. In the third Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–2.20 Å. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three FeO6 octahedra, corners with three equivalent SiO4 tetrahedra, and edges with three equivalent CsO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 58–66°. There are a spread of Al–O bond distances ranging from 1.73–1.79 Å. There are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three FeO6 octahedra, corners with three equivalent AlO4 tetrahedra, and edges with three equivalent CsO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 55–62°. There are a spread of Si–O bond distances ranging from 1.61–1.70 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three FeO6 octahedra, corners with three equivalent SiO4 tetrahedra, and edges with three equivalent CsO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 54–60°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three FeO6 octahedra, corners with three equivalent SiO4 tetrahedra, and edges with three equivalent CsO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 54–61°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted tetrahedral geometry to three Fe+2.67+ and one Al3+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Fe+2.67+ and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Fe+2.67+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Fe+2.67+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Cs1+, one Al3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Cs1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Fe+2.67+ atoms. In the eighth O2- site, O2- is bonded in a distorted T-shaped geometry to three Fe+2.67+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Cs1+, one Al3+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Cs1+, one Al3+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Cs1+ and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Cs1+ and two Si4+ atoms.