Materials Data on RbAlF4 by Materials Project
RbAlF4 crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a distorted body-centered cubic geometry to eight equivalent F1- atoms. There are four shorter (2.94 Å) and four longer (3.01 Å) Rb–F bond lengths. In the second Rb1+ site, Rb1+ is bonded in a 8-coordinate geometry to eight equivalent F1- atoms. There are four shorter (2.96 Å) and four longer (2.99 Å) Rb–F bond lengths. Al3+ is bonded to six F1- atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedra tilt angles range from 15–18°. There are a spread of Al–F bond distances ranging from 1.78–1.87 Å. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to four Rb1+ and one Al3+ atom. In the second F1- site, F1- is bonded in a linear geometry to two equivalent Al3+ atoms. In the third F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two equivalent Al3+ atoms.