Low-lying electronic states of the C6H5Cl+ ion studied using multiconfiguration wave functions

Geometries, frequencies, and energies of the 12B1, 12A2, 12B2, 22B1, 12A1, 22B2, and 32B1 states of C6H5Cl+ and potential energy curves (PECs) for Cl-loss dissociations in the 12B1, 12A2, 12B2, and 12A1 states were calculated by using the CASPT2//CASSCF methods in conjunction with an ANO basis. The CASPT2//CASSCF adiabatic excitation energies and CASPT2 relative energies for the seven states are in good agreement with experiment. The CASPT2//CASSCF PEC calculations predict the 12A2 state to correlate with C6H5+(13B1)+Cl and show importance of using multiconfiguration-based methods. The B3LYP calculations were performed for 12B1, 12A2, 12B2, and 12A1, but the PEC calculations for 12A2 were not successful.