A theoretical study of singlet low-energy excited states of the benzene dimer

Multiconfigurational second order perturbation theory (CASPT2) is used to study the binding and spectroscopy of the benzene dimer in the D6h conformation. Computed spectroscopic parameters (absorption, emission and binding energies) are in agreement with experimental data. The transformation of the excited T-shaped benzene dimer to the excimer has been found to proceed via a small barrier.