Ab initio modeling of optical properties of organic molecules and molecular complexes

Abstract

Electronic excitations are key points of most of the commonly measured optical spectra, The first principle studies of excited states however require much larger effort than computations of the ground state reliably reproduced by the density functional theory (DFT). In present work computation of optical functions of organic molecular complexes is studied. The system of independent particles excited by external light field is considered within perturbation theory (the random phase approximation, RPA). Optical response functions are calculated using ab initio pseudopotentials theory, Results of predicted optical absorption associated with organic semi-conducting conjugated polymers, poly-phenylene-vinylenes (PPV), are presented. Effects of different corrections to the DFT improving accuracy are considered. Results are discussed in comparison with available experimental data. © Springer-Verlag Berlin Heidelberg 2006.