Materials Data on Cs2RbSiF7 by Materials Project

Abstract

Cs2RbSiF7 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to six F1- atoms to form distorted CsF6 octahedra that share corners with four SiF6 octahedra and corners with six equivalent CsF6 octahedra. The corner-sharing octahedra tilt angles range from 0–68°. There are a spread of Cs–F bond distances ranging from 3.07–3.20 Å. In the second Cs1+ site, Cs1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of Cs–F bond distances ranging from 3.00–3.19 Å. Rb1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of Rb–F bond distances ranging from 2.99–3.17 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to six F1- atoms to form SiF6 octahedra that share corners with four equivalent CsF6 octahedra. The corner-sharing octahedral tilt angles are 68°. There is two shorter (1.72 Å) and four longer (1.73 Å) Si–F bond length. In the second Si4+ site, Si4+ is bonded to six F1- atoms to form SiF6 octahedra that share corners with four equivalent CsF6 octahedra. The corner-sharing octahedral tilt angles are 67°. There is two shorter (1.72 Å) and four longer (1.73 Å) Si–F bond length. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded to four Cs1+ and two equivalent Rb1+ atoms to form corner-sharing FCs4Rb2 octahedra. The corner-sharing octahedra tilt angles range from 0–25°. There are two shorter (3.00 Å) and two longer (3.07 Å) F–Cs bond lengths. Both F–Rb bond lengths are 3.03 Å. In the second F1- site, F1- is bonded in a single-bond geometry to four Cs1+ and one Si4+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to two equivalent Cs1+, two equivalent Rb1+, and one Si4+ atom. In the fourth F1- site, F1- is bonded in a distorted single-bond geometry to one Cs1+, two equivalent Rb1+, and one Si4+ atom. In the fifth F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Cs1+, one Rb1+, and one Si4+ atom. In the sixth F1- site, F1- is bonded to four Cs1+ and two equivalent Rb1+ atoms to form corner-sharing FCs4Rb2 octahedra. The corner-sharing octahedra tilt angles range from 0–25°. In the seventh F1- site, F1- is bonded to four Cs1+ and two equivalent Rb1+ atoms to form corner-sharing FCs4Rb2 octahedra. The corner-sharing octahedra tilt angles range from 0–25°. Both F–Cs bond lengths are 3.07 Å.