Xenon Hexafluoride: Structure of a Cubic Phase at -80°C

Abstract

The crystal structure of a cubic phase of composition XeF₆ has been determined at -80°C. There are no simple molecules in the complex structure which involves 1008 atoms distributed over 1600 positions per unit cell. Ions of XeF₅+ and F- are associated in tetrameric and hexameric rings of point group symmetries 4 and 32, respectively. The structure contains right-and left-handed conformations of both tetramers and hexamers. The handedness of the tetramers is dis-ordered but the orientation is ordered. The handedness of the hexamers is ordered but the orientation is disordered.