Rerefinement of the crystal structure of α-ThBr 4 .

Single crystals of α-ThBr 4 , thorium(IV) tetra-bromide, were obtained as a side product from the reaction of CuBr with β-ThBr 4 at 753 K. In the crystal structure, the Th atom (site symmetry ..) is surrounded by eight Br atoms in the form of a tetra-gonal-disphenoidal coordination polyhedron. The connectivity of these polyhedra is 3 ∞ [ThBr 4/2 Br 4/2 ]. In comparison with the previous crystal structure refinement [Mason et al. (1974 ▸). J. Less-Common Met. 35 , 331-338], the current rerefinement resulted in much higher preciscion of the lattice parameters and the atomic coordinates.