This investigation in the Theoretical and Computational Chemistry Program of the Chemistry Division involves the continued development of the correlated effective valence shell Hamiltonian method for describing the electronic structures of both small and large molecules. Adaptations are being made to massively parallel computer systems, while applications include photochemical reactions, nonadiabatic couplings in photo-dissociations, and the electronic spectra of conjugated pi-electron systems and transition-metal diatomics. %%% The continued development of theoretical methods for describing how the electrons in atoms and molecules interact with radiation and how this interaction affects the chemical reactivity of the atoms and molecules is a key thrust of this investigation in theoretical and computational chemistry.
