Resonant photoemission at the Ni 2 p core level as a probe of electron correlation effects in nickel

The observed enhancement in the 3d, 3p, and 3s photoemission structures at resonance with the 2p absorption edge of nickel is analyzed using a cluster calculation including multiplet structure. The result strongly supports the view of a localized electronic structure for nickel metal. It is found that the peak splitting in the 3s photoemission is due to d mixing, whereas the 3p photoemission shows the influence of both d mixing and electrostatic interaction.