Hollandites (AxM8O16, where A is a large cation and M is a transition metal, here vanadium) have been studied for a wide range of properties, including electronic phenomena such as metal-insulator transitions (MIT). We are currently investigating BixV8O16 and BixBayV8O16 materials showing electronic transitions that may correspond to the formation of orbital molecules (small clusters of metal-metal bonded transition metal ions in orbitally ordered states). For BixV8O16 compositions, a MIT has been observed but no low temperature structural work was reported. The high resolution of HRPD is essential to determining accurate crystal structures in these materials. Neutrons are required to determine accurate oxygen atom positions, essential for characterising charge and orbital orders.