Materials Data on RbAlF4 by Materials Project

Abstract

RbAlF4 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 3-coordinate geometry to three F1- atoms. There are one shorter (2.74 Å) and two longer (2.87 Å) Rb–F bond lengths. In the second Rb1+ site, Rb1+ is bonded in a 8-coordinate geometry to eight equivalent F1- atoms. All Rb–F bond lengths are 3.01 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six F1- atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedra tilt angles range from 1–35°. There are a spread of Al–F bond distances ranging from 1.78–1.90 Å. In the second Al3+ site, Al3+ is bonded to six F1- atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles are 30°. There is two shorter (1.77 Å) and four longer (1.85 Å) Al–F bond length. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a linear geometry to two equivalent Al3+ atoms. In the second F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Rb1+ and one Al3+ atom. In the third F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent Al3+ atoms. In the fourth F1- site, F1- is bonded in a bent 150 degrees geometry to two Al3+ atoms. In the fifth F1- site, F1- is bonded in a distorted single-bond geometry to two Rb1+ and one Al3+ atom.