Computer Experiments / Light, Absorption / Modelling / Spectroscopy. Ultruviolet /
Spectroscopy, VisibleThe UV-Vis absorption spectra of organic molecules are calculated with a new ansatz based on the simultaneous coupling of several vibrations during the electronic transition. Even with the simplest assumption of a Boltzmann weighted statistical mixing of the vibrational modes it is possible to reproduce the experimental absorption spectra, e.g. of naphthalene, surprisingly well. Using this method the homogeneous line width can be determined with an error of less than 30% from the common absorption spectra.