Time-dependent density functional theory

Time-dependent density functional theory (TDDFT) is a quantum mechanical theory used to investigate the time evolution of electronic systems. It extends the framework of density functional theory (DFT), which is primarily used for static properties of many-body quantum systems, to systems that are subject to time-dependent external perturbations, such as electric fields or laser pulses. In TDDFT, the central quantity is the electron density, which is a function of both position and time.