DOI: 10.17188/1689423
title: Materials Data on KBaNaCaTi4Fe8Si8(O19F)2 by Materials Project

description: KNaBaCaTi4Fe8Si8(O19F)2 crystallizes in the monoclinic P2/m space group. The structure is three-dimensional. K1+ is bonded in a 2-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.70–3.26 Å. Na1+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of Na–O bond distances ranging from 2.63–2.74 Å. Ba2+ is bonded in a 2-coordinate geometry to two equivalent O2- atoms. Both Ba–O bond lengths are 2.70 Å. Ca2+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of Ca–O bond distances ranging from 2.56–2.71 Å. There are two inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share a cornercorner with one TiO6 octahedra and corners with four equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ti–O bond distances ranging from 1.87–2.11 Å. In the second Ti4+ site, Ti4+ is bonded to five O2- and one F1- atom to form TiO5F octahedra that share a cornercorner with one TiO5F octahedra, a cornercorner with one FeO5F octahedra, and corners with four equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–46°. There are a spread of Ti–O bond distances ranging from 1.85–1.94 Å. The Ti–F bond length is 2.12 Å. There are three inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to five O2- and one F1- atom to form FeO5F octahedra that share a cornercorner with one TiO5F octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. There are a spread of Fe–O bond distances ranging from 1.84–2.10 Å. The Fe–F bond length is 2.04 Å. In the second Fe3+ site, Fe3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Fe–O bond distances ranging from 2.05–2.29 Å. In the third Fe3+ site, Fe3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Fe–O bond distances ranging from 1.87–2.46 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one FeO5F octahedra, corners with two equivalent TiO5F octahedra, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 27–55°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one FeO5F octahedra, corners with two equivalent TiO6 octahedra, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 24–55°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Fe3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to two equivalent K1+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Ti4+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ca2+ and two equivalent Ti4+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Fe3+ atoms. In the sixth O2- site, O2- is bonded in a linear geometry to two equivalent Si4+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to three Fe3+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a distorted tetrahedral geometry to one Ti4+ and three Fe3+ atoms. In the ninth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Fe3+ atoms. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Ca2+, one Ti4+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Si4+ and one O2- atom. The O–O bond length is 1.88 Å. In the twelfth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+, one Ti4+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a square co-planar geometry to two equivalent Ba2+ and two equivalent O2- atoms. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Ca2+, one Ti4+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Na1+ and two equivalent Ti4+ atoms. F1- is bonded in a distorted bent 120 degrees geometry to one Ti4+ and one Fe3+ atom.