Single-Crystal X-Ray Diffraction Study of β-Fluorine

Three-dimensional x-ray diffraction data from a single crystal of β-F2 have yielded a crystal structure like that later found for the γ-O2 phase in which no dimers are present. The unit cell is cubic, contains eight molecules, and has a lattice dimension of a=6.67±0.07 Å. The two molecules at 000 and ½ ½ ½ are approximately spherically disordered, and the six molecules approximately at ¼ ½ 0, ¾ ½ 0, 0 ¼ ½, 0 ¾ ½, ½ 0 ¼, and ½ 0 ¾ are highly disordered, respectively, in the planes x=¼, x=¾, y=¼, y=¾, z=¼, and z=¾. The value of R=Σ ‖ Fo |−| Fc ‖/Σ | Fo | is 0.10 for the 28 observed reflections.