Polarization effects on electronic excitation of molecules by low-energy electron impact: Study one−-furan scattering

摘要

The Schwinger multichannel method is applied to study the influence of polarization effects on the electronic excitation of the furan molecule by low-energy electron impact. We discuss the importance of inclusion of these effects through the comparison of theoretical results for the electronic excitation of the B3 2 state of furan obtained with and without the proper treatment of the polarization of the target. The electron-furan scattering presents two prominent shape resonances in the A2 2 and B2 1 symmetries at around the electronic excitation threshold of the B3 2 state (3.7 eV). At this low-energy, the inclusion of polarization effects in the calculation moves to lower energies the resonances positions obtained either in the close-coupling or in the static-exchange level of approximation. This phenomenon strongly influences the electronic excitation process. The present results show that a simple close-coupling calculation cannot be applied for molecular systems with low-energy electronic excitation thresholds around misplaced resonances. © 2008 The American Physical Society.