Absorption and emission spectroscopy of molecular trimers: Cyclic versus linear geometries

The spectroscopic properties of molecular trimers are studied within a model where three degenerate electronically excited states are coupled via dipole-dipole interactions. Taking a single vibrational degree of freedom for each monomer into account, this results in a non-adiabatic nuclear dynamic which determines features of the spectra. The cases of a cyclic and a linear coupling scheme are regarded and it is investigated how these different geometries influence the absorption and emission spectra.