I have chosen many of these to be relatively inexpensive (i.e., Dover editions are available) or, at least at the time of this writing, available in electronic form via the university library. You may need to load using the library proxy.
- The Craft of Research, Booth et al. Explains how to form research questions, gather evidence, and present that evidence.
- Electronic structure, Richard Martin: Electronic structure methods, mostly density functional theory. Available at the UIUC library.
- Quantum theory of many-particle systems, Fetter and Walecka: RPA, perturbation theory, Feynman diagrams
- Modern quantum chemistry, Szabo and Ostlund: Quantum chemistry techniques, configuration interaction, …
- Group theory and quantum mechanics, Tinkham: Representation of groups, symmetry groups.
- The art of data science. Peng and Matsui: A holistic, relatively short intro on how to approach data problems