DOI: 10.17188/1716953
title: Materials Data on Ca4Fe5(Si3O14)2 by Materials Project

description: Ca4Fe5(Si3O14)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded to seven O atoms to form distorted CaO7 pentagonal bipyramids that share corners with five SiO4 tetrahedra, edges with three FeO6 octahedra, and an edgeedge with one SiO4 tetrahedra. There are a spread of Ca–O bond distances ranging from 2.33–2.62 Å. In the second Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.32–2.51 Å. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four SiO4 tetrahedra, edges with two equivalent FeO6 octahedra, and an edgeedge with one CaO7 pentagonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.86–2.14 Å. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four SiO4 tetrahedra, edges with two equivalent FeO6 octahedra, and an edgeedge with one CaO7 pentagonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.85–2.13 Å. In the third Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four SiO4 tetrahedra and edges with two equivalent CaO7 pentagonal bipyramids. There are a spread of Fe–O bond distances ranging from 1.81–2.13 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four FeO6 octahedra, a cornercorner with one SiO4 tetrahedra, and an edgeedge with one CaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 49–57°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with five FeO6 octahedra and corners with two equivalent CaO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 43–61°. There is three shorter (1.65 Å) and one longer (1.66 Å) Si–O bond length. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with three equivalent CaO7 pentagonal bipyramids, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Si–O bond distances ranging from 1.63–1.70 Å. There are fourteen inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to two Fe and one Si atom. In the second O site, O is bonded in a water-like geometry to two Fe atoms. In the third O site, O is bonded in a distorted rectangular see-saw-like geometry to two Ca, one Fe, and one Si atom. In the fourth O site, O is bonded in a distorted trigonal planar geometry to two Ca and one Si atom. In the fifth O site, O is bonded in a bent 150 degrees geometry to one Ca and one Si atom. In the sixth O site, O is bonded in a water-like geometry to two Fe atoms. In the seventh O site, O is bonded in a trigonal planar geometry to one Ca, one Fe, and one Si atom. In the eighth O site, O is bonded in a trigonal planar geometry to one Ca, one Fe, and one Si atom. In the ninth O site, O is bonded in a distorted rectangular see-saw-like geometry to one Ca, two Fe, and one Si atom. In the tenth O site, O is bonded in a distorted trigonal planar geometry to one Ca, one Fe, and one Si atom. In the eleventh O site, O is bonded in a distorted trigonal planar geometry to one Ca, one Fe, and one Si atom. In the twelfth O site, O is bonded in a water-like geometry to one Ca and one Fe atom. In the thirteenth O site, O is bonded in a distorted trigonal non-coplanar geometry to one Ca, one Fe, and one Si atom. In the fourteenth O site, O is bonded in a 3-coordinate geometry to one Ca and two Si atoms.