Core hole effect in NEXAFS spectroscopy of aromatic hydrocarbons: Chrysene, perylene and coronene

NEXAFS spectra of chrysene, perylene and coronene were measured using synchrotron radiation, and were analyzed by ab initio MO calculations. The spectra do not correspond well to the calculated density of unoccupied states (DOUS) nor the reported inverse photoemission spectra, indicating large core-hole effects leading deviation of NEXAFS spectra from DOUS. On the other hand, the observed spectra were well simulated by theoretical calculations taking account of the core-hole effect by the hole potential method, allowing detailed analysis of the core-hole effect in these systems.