DOI: 10.17188/1750810
title: Materials Data on Na4Ca4Ti4Si4O22F3 by Materials Project

description: Na4Ca4Ti4Si4O22F3 is Esseneite-derived structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Na sites. In the first Na site, Na is bonded in a 8-coordinate geometry to six O and two F atoms. There are a spread of Na–O bond distances ranging from 2.55–2.75 Å. There are one shorter (2.15 Å) and one longer (2.22 Å) Na–F bond lengths. In the second Na site, Na is bonded in a 8-coordinate geometry to six O and two F atoms. There are a spread of Na–O bond distances ranging from 2.55–2.75 Å. There are one shorter (2.15 Å) and one longer (2.22 Å) Na–F bond lengths. There are two inequivalent Ca sites. In the first Ca site, Ca is bonded to five O and one F atom to form distorted CaO5F octahedra that share corners with four SiO4 tetrahedra, edges with two equivalent CaO5F octahedra, and edges with two TiO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.31–2.48 Å. The Ca–F bond length is 2.25 Å. In the second Ca site, Ca is bonded to five O and one F atom to form distorted CaO5F octahedra that share corners with four SiO4 tetrahedra, edges with two equivalent CaO5F octahedra, and edges with two TiO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.33–2.46 Å. The Ca–F bond length is 2.24 Å. There are two inequivalent Ti sites. In the first Ti site, Ti is bonded to six O atoms to form TiO6 octahedra that share corners with four TiO6 octahedra, corners with two SiO4 tetrahedra, and edges with two CaO5F octahedra. The corner-sharing octahedra tilt angles range from 36–46°. There are a spread of Ti–O bond distances ranging from 1.92–2.04 Å. In the second Ti site, Ti is bonded to six O atoms to form TiO6 octahedra that share corners with four TiO6 octahedra, corners with two SiO4 tetrahedra, and edges with two CaO5F octahedra. The corner-sharing octahedra tilt angles range from 36–46°. There are a spread of Ti–O bond distances ranging from 1.92–2.04 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two TiO6 octahedra, corners with four CaO5F octahedra, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–57°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two TiO6 octahedra, corners with four CaO5F octahedra, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 43–57°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. There are twelve inequivalent O sites. In the first O site, O is bonded in a 4-coordinate geometry to one Na, one Ca, one Ti, and one Si atom. In the second O site, O is bonded in a distorted trigonal planar geometry to two Ca and one Si atom. In the third O site, O is bonded in a 4-coordinate geometry to one Na, one Ca, one Ti, and one Si atom. In the fourth O site, O is bonded in a 4-coordinate geometry to two equivalent Na and two equivalent Ti atoms. In the fifth O site, O is bonded to two Ca and two Ti atoms to form distorted OCa2Ti2 tetrahedra that share corners with two equivalent FNa2Ca2 tetrahedra. In the sixth O site, O is bonded in a distorted trigonal planar geometry to two Ca and one Si atom. In the seventh O site, O is bonded in a 4-coordinate geometry to two equivalent Na and two equivalent Ti atoms. In the eighth O site, O is bonded in a distorted bent 150 degrees geometry to two Na and two Si atoms. In the ninth O site, O is bonded in a 4-coordinate geometry to two Na and two Ti atoms. In the tenth O site, O is bonded in a 4-coordinate geometry to two Na and two Ti atoms. In the eleventh O site, O is bonded in a 4-coordinate geometry to one Na, one Ca, one Ti, and one Si atom. In the twelfth O site, O is bonded in a 4-coordinate geometry to one Na, one Ca, one Ti, and one Si atom. There are two inequivalent F sites. In the first F site, F is bonded to four Na atoms to form corner-sharing FNa4 tetrahedra. In the second F site, F is bonded to two Na and two Ca atoms to form FNa2Ca2 tetrahedra that share corners with two equivalent OCa2Ti2 tetrahedra and corners with two equivalent FNa4 tetrahedra.