An accurate reappraisal of the elemental form factors and charge density of copper

The best X-ray atomic scattering factors for copper have been examined carefully to see which are most appropriate for charge density studies. The most consistent values were then used to generate a deformation charge density map, and it would appear that bonding in copper arises from electron charge build up between nearest-neighbour (n.n.) atoms, next-n.n. atoms etc. This is in agreement with conclusions obtained from γ-ray diffraction experiments and the best band-structure calculations, but in marked disagreement with the charge density obtained from earlier band-structure form factors.