Ludwik Adamowicz is supported by a grant from the Theoretical and Computational Chemistry Program to develop a state-selective multireference coupled-cluster approach to electron correlation in quantum chemistry. This method produces accurate potential energy surfaces of both ground and excited states, including bond making and breaking processes. This method will handle complete-active-space reference functions, incorporate spin adaptation and first-order response, and execute via an efficient production code. Additionally, several applications of the new methodology will be pursued, including the photophysics of nucleic acid bases, carbon clusters, and silicon clusters. One of the major goals of theoretical chemisty is the computation of potential energy surfaces of molecular excited states, of sufficient accuracy to describe the dynamics of transformations such as bond breakage and formation. Excited state processes play a major role in photochemistry, and thus have relevance in astrophysics as well as ultraviolet-induced reactions of nucleic acids.
