"Electronic Structure Modeling" enables non-specialists to employ computational chemistry methods, including electronic structure calculations, to their investigations. Featuring electronic structure codes, this unique text illustrates theoretical methods with numerical detail and model calculations. It clarifies what these modeling programs can do, their known pathologies, which ones are suited for specific kinds of projects, and how to reproduce them using the accompanying PC-LOBE bundled software. While elucidating gradient-based molecular structure optimization, this text reviews notable successes and unsolved problems or failures in electronic structure modeling. It includes numerous tables, graphs, and figures throughout.