TY - JOUR TI - The exciton model in molecular spectroscopy AU - Michael Kasha AU - H. Ralph Rawls AU - M. Ashraf El‐Bayoumi PY - 1965 JO - Pure and Applied Chemistry DO - 10.1351/pac196511030371 UR - https://doi.org/10.1351/pac196511030371 AB - The molecular exciton model has received its most extensive development and application in the field of molecular crystals1'2. More recently, numerous applications to non-crystalline molecular composite systems have been made, including van der Waals and hydrogen-bonded dimers, trimers, and ER -