Materials Data on AlTl2OF5 by Materials Project

Abstract

Tl2AlOF5 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Tl2+ is bonded to one O2- and four F1- atoms to form distorted TlOF4 square pyramids that share corners with four equivalent AlF6 octahedra, corners with two equivalent TlOF4 square pyramids, and a faceface with one TlOF4 square pyramid. The corner-sharing octahedra tilt angles range from 57–65°. The Tl–O bond length is 2.23 Å. There are two shorter (2.62 Å) and two longer (2.72 Å) Tl–F bond lengths. Al3+ is bonded to six F1- atoms to form AlF6 octahedra that share corners with two equivalent AlF6 octahedra and corners with eight equivalent TlOF4 square pyramids. The corner-sharing octahedral tilt angles are 16°. There are a spread of Al–F bond distances ranging from 1.81–1.87 Å. O2- is bonded in a water-like geometry to two equivalent Tl2+ atoms. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Tl2+ and one Al3+ atom. In the second F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Tl2+ and one Al3+ atom. In the third F1- site, F1- is bonded in a linear geometry to two equivalent Al3+ atoms.