The Cu 2p x-ray-photoemission spectrum (XPS) of copper (II) acetylacetonate Cu(acac${)}_2$ is measured. Both the 2${\mathit{p}}_{3/2}$ and 2${\mathit{p}}_{1/2}$ XPS show triple-peak features, which resemble the Ni 2p XPS in ${\mathrm{NiCl}}_2$. By means of a cluster model, however, it is shown that the origin of the triple-peak feature in Cu(acac${)}_2$ is quite different from that in Ni dihalides. In Cu(acac${)}_2$, the main peak originates from one well-screened final state (2${\mathit{p}}^5$3${\mathit{d}}^{10}$L), where L denotes a ligand hole, while the two satellite peaks comes from the bonding and antibonding states between the other well-screened state and a poorly screened state (2${\mathit{p}}^5$3${\mathit{d}}^9$). The energy splitting in the 2${\mathit{p}}^5$3${\mathit{d}}^{10}$L states originates from strong hybridization between O 2p and C 2p orbitals.

• Received 3 May 1993

DOI:https://doi.org/10.1103/PhysRevB.48.10733