Our research program focuses on (i) ab initio quantum theory of molecular electronic structure and other many-body systems, (ii) molecular properties, spectroscopy, and photochemistry, (iii) reaction mechanisms and dynamics, and (iv) theory of intermolecular forces. We design and apply quantum mechanical methods that enable precise determination of potential energy surfaces and property functions for both existing and hypothetical molecular species in their ground and excited states. We are also interested in accurate quantum calculations for strongly correlated systems, weakly bound clusters, and atomic nuclei.