UC Berkeley

This thesis is primarily concerned with the development of tools aiming to improve the efficiency of electronic structure calculations using modern density functional theory (DFT), and to utilize the results of DFT-based energy decomposition analysis (EDA) for probing and modeling intermolecular interactions. It covers three distinct while also related topics: (i) development of a novel scheme to perform self-consistent field (SCF) calculations using a minimal adaptive basis (MAB) that is optimized on-the-fly; (ii) development and assessment of energy decomposition analysis (EDA) methods, including a new EDA scheme that is capable of probing the observable effects of intermolecular interactions, and a thorough discussion on the definition of the charge-transfer term in EDA methods; (iii) application of EDA to the development of potential energy surfaces for molecular simulations, including an assessment of the AMOEBA polarizable force field, and the formulation, implementation, and analysis of a mutually polarizable QM/MM scheme employing AMOEBA.