Materials Data on Fe15(Ge2O9)4 by Materials Project
Fe15(Ge2O9)4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are eight 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 corners with five GeO4 tetrahedra and edges with five FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.97–2.23 Å. In the second Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent FeO4 tetrahedra, corners with six GeO4 tetrahedra, and edges with three FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.10–2.26 Å. In the third Fe+2.67+ site, Fe+2.67+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with eight FeO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–67°. There are a spread of Fe–O bond distances ranging from 1.91–1.95 Å. In the fourth Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent FeO4 tetrahedra, corners with three GeO4 tetrahedra, and edges with five FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.99–2.10 Å. In the fifth Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one FeO4 tetrahedra, corners with five GeO4 tetrahedra, and edges with four FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.98–2.09 Å. In the sixth Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one FeO6 octahedra, a cornercorner with one FeO4 tetrahedra, corners with four GeO4 tetrahedra, and edges with four FeO6 octahedra. The corner-sharing octahedral tilt angles are 23°. There are a spread of Fe–O bond distances ranging from 2.06–2.13 Å. In the seventh Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share a cornercorner with one FeO6 octahedra, a cornercorner with one FeO4 tetrahedra, corners with five GeO4 tetrahedra, and edges with four FeO6 octahedra. The corner-sharing octahedral tilt angles are 23°. There are a spread of Fe–O bond distances ranging from 2.07–2.31 Å. In the eighth Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent FeO4 tetrahedra, corners with four GeO4 tetrahedra, and edges with four FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.03–2.08 Å. There are four inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with seven FeO6 octahedra and a cornercorner with one GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–58°. There are a spread of Ge–O bond distances ranging from 1.76–1.83 Å. In the second Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with seven FeO6 octahedra and a cornercorner with one FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Ge–O bond distances ranging from 1.77–1.79 Å. In the third Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with eight FeO6 octahedra and a cornercorner with one FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of Ge–O bond distances ranging from 1.77–1.82 Å. In the fourth Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with eight FeO6 octahedra and a cornercorner with one GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–59°. There are a spread of Ge–O bond distances ranging from 1.76–1.82 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded to four Fe+2.67+ atoms to form a mixture of distorted corner and edge-sharing OFe4 trigonal pyramids. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.67+ and one Ge4+ atom. In the third O2- site, O2- is bonded to three Fe+2.67+ and one Ge4+ atom to form distorted OFe3Ge trigonal pyramids that share a cornercorner with one OFe4 trigonal pyramid and an edgeedge with one OFe3Ge trigonal pyramid. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to one Fe+2.67+ and two Ge4+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.67+ and one Ge4+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.67+ and one Ge4+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.67+ and one Ge4+ atom. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Fe+2.67+ and one Ge4+ atom. In the ninth O2- site, O2- is bonded in a trigonal planar geometry to two Fe+2.67+ and one Ge4+ atom. In the tenth O2- site, O2- is bonded to four Fe+2.67+ atoms to form distorted corner-sharing OFe4 trigonal pyramids. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.67+ and one Ge4+ atom. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.67+ and one Ge4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.67+ and one Ge4+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.67+ and one Ge4+ atom. In the fifteenth O2- site, O2- is bonded in a distorted see-saw-like geometry to four Fe+2.67+ atoms. In the sixteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.67+ and one Ge4+ atom. In the seventeenth O2- site, O2- is bonded in a trigonal planar geometry to two Fe+2.67+ and one Ge4+ atom. In the eighteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Fe+2.67+ and one Ge4+ atom.