Rerefinement of the crystal structure of BiF5

Redetermination of the crystal structure of BiF₅ was undertaken to a much higher precision and quantum chemical calculations for an assignment of the Raman and IR bands.

The crystal structure of bis­muth penta­fluoride, 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 octa­hedral coordination environment. The [BiF₆] octa­hedra 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.