Rerefinement of the crystal structure of BiF₅

The crystal structure of bis-muth penta-fluoride, BiF₅, was rerefined from single-crystal data. BiF₅ crystallizes in the α-UF₅ structure type in the form of colorless needles. In comparison with the previously reported crystal-structure model [Hebecker (1971 ▸). Z. Anorg. Allg. Chem. 384, 111-114], the lattice parameters and fractional atomic coordinates were determined to much higher precision and all atoms were refined anisotropically, leading to a significantly improved structure model. The Bi atom (site symmetry 4/m..) is surrounded by six F atoms in a distorted octa-hedral coordination environment. The [BiF₆] octa-hedra are corner-linked to form infinite straight chains extending parallel to [001]. Density functional theory (DFT) calculations at the PBE0/TZVP level of theory were performed on the crystal structure of BiF₅ to calculate its IR and Raman spectra. These are compared with experimental data.