Karl Freed of the University of Chicago is supported by the Theoretical and Computational Chemistry Program to continue the development of the correlated effective valence shell Hamiltonian method for describing the electronic structure of large molecules. Applications include photochemical reactions, nonadiabatic couplings in photodissociations, electronic spectra of conjugated pi-electron systems, and biological chromophores in their native protein environments. The development of theoretical tools for describing how electrons in atoms and molecules interact with radiation and how this interaction affects the chemical reactivity of the atoms and molecules is key to understanding and predicting much of photochemistry. In particular, the theoretical studies of protein chromophores are an important contribution to the understanding of photoreactive biological systems.
