Core shell excitation of furan at the O1s and C1s edges:: An experimental and ab initio study

The K-shell spectra of gaseous furan have been measured using the inner-shell electron energy loss spectroscopy (ISEELS) method at the carbon and oxygen thresholds. Large-scale ab initio configuration interaction calculations have been carried out in order to help in the assignments of the observed bands. The spectra are close to previous low resolution ones obtained using ISEELS in the gas phase and photoabsorption with the synchrotron radiation in gaseous and condensed phases. The presence of a new feature located at 287.3 eV in the C1s spectrum and recently detected by photoabsorption with synchrotron radiation is confirmed. At both edges, the calculations confirm the assignments proposed in earlier experimental works, with the exception of several C1s pre-edge features for which a new interpretation is given. (C) 2003 American Institute of Physics.