This volume contains the talks presented at the International Symposium on Electronic Excitations and Interaction Processes in Organic Molecular Aggre gates which was held at Schloss Elmau, Bavaria, Germany from June 5 to June 10, 1983. In the recent years the investigation of organic materials has developed rapidly and has led to the construction of materials with interesting proper ties. The discovery of highly conducting and superconducting organic materials is definitely one of the reasons for the enormous increase in research acti vity in this field. Interesting applications have been realized or seem pos sible, such as the application of organic materials in electrophotography. The conductivity of organic polymers may be varied within a large range by doping and such materials have been used to construct an organic battery. Some time ago it was suggested that organic glasses and polymers could be used as stor age materials in computer technology. With the development of preparation tech niques and modern methods of investigation, for example, high resolution and picosecond spectroscopy, a large amount of experimental data is available not only for the conducting materials but also for organic semiconductors and in sulators. With this rapid accumulation of experimental material the microscopic theoretical understanding could not keep pace.

Autorentext
Hermann Haken is Professor of the Institute for Theoretical Physics at the University of Stuttgart. He is known as the founder of synergetics. His research has been in nonlinear optics (in particular laser physics), solid state physics, statistical physics, and group theory. After the implementation of the first laser in 1960, Professor Haken developed his institute to an international center for laser theory. The interpretation of the laser principles as self organization of non equilibrium systems paved the way to the development of synergetics, of which Haken is recognized as the founder. Hermann Haken has been visiting professor or guest scientist in England, France, Japan, USA, Russia, and China. He is the author of some 23 textbooks and monographs that cover an impressive number of topics from laser physics to synergetics, and editor of a book series in synergetics. For his pathbreaking work and his influence on academic research, he has been awarded many-times. Among others, he is member of the Order "Pour le merite" and received the Max Planck Medal in 1990.

Inhalt
I Basic Concepts, Methods and Results.- Excited State Interaction and Energy Transfer Between Molecules in Organic Crystals Basic Experimental Methods and Results.- Electronic Excitations in Molecular Solids.- II Interaction of Electronic Excitations with Electromagnetic Radiation.- Excitation Spectroscopy of Triplet State Monomers, Aggregates and Excitons in Anthracene Crystals.- Photoemission from Molecular Crystals, Bandstructure and Resonance Effects.- New Type of Local Resonances in Thin Rough Films.- III Electronic Excitations and Spin Dynamics.- Electron Spin Echo Spectroscopy of One-Dimensional Excitons.- Energy Transfer in Molecular Crystals and Its Influence on Spin Resonance.- Ensemble Averaged Spin Pair Dynamics of Doublet and Triplet Molecules.- IV Interaction of Electronic Excitations with Lattice Vibrations.- Localization and Delocalization of an Exciton in the Phonon Field.- Vibronic Excitons in the Intermediate Coupling Regime.- Photo-Induced Electron or Excitation Transfer Enhanced During Vibrational Relaxation and Generalized Förster's Formula.- Molecular Aggregates in Liquids Resolved by a Novel Raman Spectroscopy.- V Excimers, Charge Transfer Excitons and Exciton Fission.- Charge Transfer Spectra of Aromatic Hydrocarbon Crystals.- Exciton Band Structure and Excimer Formation.- Fission and Radiation!ess Transitions in Organic Molecular Crystals in Highly Excited States.- VI Electronic Excitations in Disordered Systems.- Transport and Thermodynamics of Physical Systems with Fractal Geometry.- Hopping Transport in Disordered Systems.- Energy Transfer and Relaxation Processes as Studied by Picosecond Fluorescence Spectroscopy.- Theoretical Methods for the Analysis of Exciton Capture and Annihilation.- Excitation Transport in NaphthaleneAggregates: Mixed Crystals, Amorphous Thin Films and Polymeric Glasses.- VII Electronic Excitation of Impurities in Glasses and Polymers.- Dynamical Linewidth Effects of Hole Burning of Free Base Phthalocyanine in Polymers: Spectral Diffusion and Exchange Narrowing.- Theory of Dephasing of Impurities in Glasses.- VIII Conductivity and Superconductivity in Organic Materials.- Spin Resonance and Conductivity of F1uoranthenyl Radical Cation Salts.- Conducting Polymers Derived from Pyrrole.- Organic Superconductors: Quasi One-Dimensional Conductors, Anomalous Superconductors.- IX Electronic Excitations in Photosynthetic Systems.- Optical Investigations of Photosynthetic Systems.- Index of Contributors.