title: Electronic circular dichroism in exciton-coupled dimers: vibronic spectra from a general all-coordinates quantum-dynamical approach.
abstract: We present a computational approach of general applicability to simulate the vibronic line shapes of absorption and electronic circular dichroism (ECD) spectra in rigid exciton-coupled dimers based on a time-dependent expression of the spectra and quantum dynamical calculations. We adopt a diabatic model of interacting states localized on the monomers whose electronic potential energy surfaces are described within harmonic approximation, including the effect of displacements, frequency changes, and normal-mode mixings. Spectra that fully account for the effect of all nuclear degrees of freedom of the system are obtained through a hierarchical representation of the Hamiltonian in blocks, defined so that few blocks accurately describe the short-time dynamics of the system. With this approach, on the ground of time-dependent density functional theory calculations, we simulate the absorption and ECD spectra of a covalent compound representing a "dimer" of anthracene, in the spectral region of the (1)La monomer transition, obtaining results in good agreement with the experiment.
authors.affiliation: Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Pisa, via Risorgimento 35, I-56126 Pisa, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Padula
authors.forename: David
authors.initials: D
authors.lastname: Picconi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Lami
authors.forename: Gennaro
authors.initials: G
authors.lastname: Pescitelli
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Santoro