Complementary Roles of Co2pX-Ray Absorption and Photoemission Spectra in CoO

We investigate the Co 2 p core-level X-ray absorption (XAS) and photoemission spectra (XPS) in CoO on the basis of a CoO 6 cluster model, where Co 3 d -O 2 p hybridization and multiplet coupling are fully taken into account. We pay particular attention to the effects of multiplet coupling on the XPS and those of Co 3 d -O 2 p hybridization on the XAS, because those points have been disregarded in the analyses made so far by many authors. From the combined analysis, we show that the XPS and XAS provide us with complementary information on the electronic states of CoO.