Materials Data on Rb3Sc2Si4(O2F)5 by Materials Project

Abstract

Rb3Sc2Si4(O2F)5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are three inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 10-coordinate geometry to four equivalent O2- and six F1- atoms. There are two shorter (3.00 Å) and two longer (3.15 Å) Rb–O bond lengths. There are a spread of Rb–F bond distances ranging from 3.01–3.33 Å. In the second Rb1+ site, Rb1+ is bonded in a 6-coordinate geometry to four O2- and six F1- atoms. There are two shorter (3.06 Å) and two longer (3.20 Å) Rb–O bond lengths. There are a spread of Rb–F bond distances ranging from 2.97–3.50 Å. In the third Rb1+ site, Rb1+ is bonded in a 5-coordinate geometry to three O2- and two equivalent F1- atoms. There are two shorter (3.01 Å) and one longer (3.13 Å) Rb–O bond lengths. Both Rb–F bond lengths are 2.87 Å. Sc3+ is bonded to two O2- and four F1- atoms to form ScO2F4 octahedra that share corners with three equivalent ScO2F4 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–11°. There are one shorter (2.04 Å) and one longer (2.07 Å) Sc–O bond lengths. There are a spread of Sc–F bond distances ranging from 2.02–2.11 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 ScO2F4 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 1.61–1.67 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one ScO2F4 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Rb1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Rb1+ and two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Rb1+, one Sc3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Rb1+, one Sc3+, and one Si4+ atom. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a linear geometry to two equivalent Rb1+ and two equivalent Sc3+ atoms. In the second F1- site, F1- is bonded in a linear geometry to two Rb1+ and two equivalent Sc3+ atoms. In the third F1- site, F1- is bonded in a distorted linear geometry to two Rb1+ and two equivalent Sc3+ atoms. In the fourth F1- site, F1- is bonded in a distorted single-bond geometry to four Rb1+ and one Sc3+ atom.