The practical foundation of modern density functional theory (DFT) was established in the Hohenberg− Kohn theorems 1 more than 50 years ago. The theory is based on first principles and allows material property predictions without requiring any prior knowledge or the ability to synthesize the material. Over the past decades, DFT has rapidly matured and is now considered indispensable in the modeling toolbox of physicists, chemists, material scientists, and engineers. The rise and success of DFT goes hand in hand with more powerful computing hardware, faster algorithms, and smarter workflows. Today, computational researchers can investigate and accurately predict the physical and chemical properties of systems of up to about a thousand atoms; moreover, the simulations are sufficiently fast to build massive databases for crystalline (bulk) materials, such as the Materials Project, 2 Open Quantum Materials Database, 3, 4 or Novel Materials Discovery. 5