The electronic states of furan studied by VUV absorption, near-threshold electron energy-loss spectroscopy and ab initio multi-reference configuration interaction calculations Original Research Article

The results of large-scale ab initio CI calculations on the electronic states of furan, using a multi-reference multi-root CI method (MRD-CI), are related to new VUV absorption and low-energy electron energy-loss (EEL) measurements, leading to detailed spectral assignments. All of the expected 1,3ππ∗ states have been assigned, there being improved agreement between theoretical and experimental energies in all cases. A number of new Rydberg series has been identified by experiment and, for these also, the calculations perform well. In addition, cationic states and ground state molecular electronic properties have been computed.