The structural properties (lattice parameter, lattice angle and Cu-I bond length) of CuI are summarised in Table , where good agreement is found between the calculated values and both the experimental and computational literature. The PBEsol lattice parameters are slightly underestimated compared to room temperature neutron powder diffraction measurements by Keen et al., while the PBE0 results show closer agreement. Low temperature diffraction data is scarcely reported, but is expected to yield lattice parameters closer to the PBEsol results. Thin film CuI often displays slightly larger lattice parameters (6.06 Å from Moditswe et al.) owing to tensile strain between film and substrate.