It is proposed to continue and extend a project concerned with excitation-transfer in ordered and disordered Molecular aggregates. This study includes localized and extended electronic, vibrational and rotational excitons in mixed and neat molecular solids and liquids. Exciton Percolation and its relation to cluster and conglomerate states will be investigated in absorption and emission ultraviolet spectra, as well as Raman, infrared and optical-microwave double resonance techniques, from 1 degree K to room temperature and above. Exciton-Phonon interaction parameters will be investigated in the same organic systems, and their role in determining the nature of energy transfer clarified. Phonon structures and densities-of-states will be studied in both neat and amorphous organic condensed phases and related to molecular interaction parameters. These parameters will also be studied in relation to first and higher order Phase transitions with special emphasis on the nature of solid-liquid transitions. The long range goal is a model for a "computer" based on molecular excitons and its application to the functioning of the brain and nervous system.