Ground and excited state polarizabilities and dipole transition properties of benzene from coupled cluster response theory

摘要

The electronic properties and transition properties have been investigated for the lowest singlet electronic states of benzene using coupled cluster response theory. The polarizabilities have been calculated for the ground state and the 1~1B_2u, 1~1B_1u 1~1E_1u and 2~1E_1u excited states. The dipole allowed transitions out of these states have also been calculated and discussed in the context of the calculated polarizabilities. Oscillator strengths and the second electronic moments of the charge distributions have been used to characterize and identify qualitative features of the individual states. The performance of coupled cluster singles (CCS), the recently proposed CC2 model, and coupled cluster singles and doubles (CCSD) is compared. It is demonstrated that the choice of basis set and electronic structure model can dramatically effect the calculated transition properties and electronic properties. An interesting disagreement with previous theoretical studies has been found in the characterization of the qualitative features of the 1~1E_1u and 2~1E_1u states.