Conventional diffraction experiments using thermal neutrons were performed in the range of momentum transfer between 1 Å−1and 8 Å−1over the total concentration range of the Bi-Cu system. The coherent differential scattering cross section of each liquid alloy was determined and compared with models. The structure of the molten pure elements copper and bismuth as well as of those alloys containing only 10 or 20 at. % of the second component can be described by hard-sphere models.