A snapshot of time-dependent density-functional theory

Time-dependent density functional theory (TDDFT) is an extension of ground-state density-functional theory, which allows the treatment of electronic excited states and a wide range of time-dependent phenomena in the linear and nonlinear regime, including coupled electron–nuclear dynamics. TDDFT is a vibrant field with many exciting applications in physics, (bio)chemistry, materials science, and other areas. This perspective gives an overview of recent developments and successes, formal and computational challenges, and hot topics in TDDFT.