DOI: 10.17188/1736593
title: Materials Data on Cs2ErSi6O14F by Materials Project

description: Cs2ErSi6O14F crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. there are three inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 8-coordinate geometry to seven O2- and one F1- atom. There are a spread of Cs–O bond distances ranging from 3.16–3.48 Å. The Cs–F bond length is 3.27 Å. In the second Cs1+ site, Cs1+ is bonded in a 2-coordinate geometry to seven O2- atoms. There are a spread of Cs–O bond distances ranging from 3.15–3.65 Å. In the third Cs1+ site, Cs1+ is bonded in a 8-coordinate geometry to seven O2- and one F1- atom. There are a spread of Cs–O bond distances ranging from 3.16–3.59 Å. The Cs–F bond length is 3.50 Å. Er3+ is bonded to four O2- and two F1- atoms to form ErO4F2 octahedra that share corners with two equivalent ErO4F2 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 24–26°. There are a spread of Er–O bond distances ranging from 2.21–2.25 Å. There are one shorter (2.24 Å) and one longer (2.25 Å) Er–F bond lengths. There are six 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 ErO4F2 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 42°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is one shorter (1.62 Å) and three longer (1.63 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one ErO4F2 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 15°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one ErO4F2 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 13°. There are a spread of Si–O bond distances ranging from 1.59–1.67 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one ErO4F2 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is two shorter (1.62 Å) and two longer (1.64 Å) Si–O bond length. There are seventeen inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to two Cs1+, one Er3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Cs1+ and two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to two Cs1+, one Er3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Cs1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Cs1+ and two equivalent Si4+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to two Cs1+, one Er3+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Cs1+ and two equivalent Si4+ atoms. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cs1+ and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fourteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fifteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms. In the sixteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cs1+ and two equivalent Si4+ atoms. In the seventeenth O2- site, O2- is bonded in a 2-coordinate geometry to two Cs1+, one Er3+, and one Si4+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent Cs1+ and two equivalent Er3+ atoms. In the second F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Cs1+ and two equivalent Er3+ atoms.