DOI: 10.17188/1734199
title: Materials Data on Cs2ErSi4O10F by Materials Project

description: Cs2ErSi4O10F crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are four inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Cs–O bond distances ranging from 3.25–3.47 Å. In the second Cs1+ site, Cs1+ is bonded in a 4-coordinate geometry to eight O2- atoms. There are a spread of Cs–O bond distances ranging from 3.15–3.47 Å. In the third Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Cs–O bond distances ranging from 3.23–3.55 Å. In the fourth Cs1+ site, Cs1+ is bonded in a 4-coordinate geometry to four O2- atoms. All Cs–O bond lengths are 3.23 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 octahedral tilt angles are 9°. There are a spread of Er–O bond distances ranging from 2.22–2.24 Å. Both Er–F bond lengths are 2.27 Å. There are four 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 29°. 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 SiO4 tetrahedra that share a cornercorner with one ErO4F2 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 33°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. 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 46°. 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 47°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Cs1+ and two Si4+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent Si4+ atoms. In the third O2- site, O2- is bonded in a linear geometry to one Cs1+ and two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cs1+ and two equivalent Si4+ atoms. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cs1+ and two equivalent Si4+ atoms. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cs1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Cs1+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Cs1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees 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 one Cs1+, one Er3+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Cs1+, one Er3+, and one Si4+ atom. In the twelfth 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 linear geometry to two equivalent Er3+ atoms. In the second F1- site, F1- is bonded in a linear geometry to two equivalent Er3+ atoms.