Advances in basic theory and computational methods have brought the study of molecular electronic structure to the point where theory/computation play a central role in the progress of the field. Professor Lester's research efforts are focused on theoretical studies of the electronic structure of molecules. Efforts in the former area are directed to extending the powerful quantum Monte Carlo method to the range of chemical problems that form the traditional domain of quantum chemistry, and beyond because of the capability of not imposing the Born-Oppenheimer approximation. Research by the Lester group has confirmed that highly accurate ground state and excited state energies are attainable by the method. Properties other than the energy including dipole and quadrupole moments as well as matrix elements connecting different electronic states (oscillator strengths and lifetimes) have been determined following algorithms developed by his group.