Excitedstate
An excited state is a state of higher energy than a system's ground state, most often referring to electronic states of atoms and molecules. In addition to electronic excitation, vibrational and rotational excitations also exist, but the term excited state in chemistry usually denotes electronic excitation that changes the electron configuration.
Electronic excitation occurs when a particle absorbs a photon or gains energy from another source, promoting
Relaxation from an excited state can proceed radiatively, emitting a photon (fluorescence from singlet states; phosphorescence
Experimental probes include UV–visible absorption spectroscopy, which detects transitions from the ground state to excited states,
Theoretical descriptions use quantum chemistry methods. Time-dependent density functional theory (TD-DFT) is widely used to predict
Excited states play central roles in many phenomena and technologies, including vision and photosynthesis, fluorescent imaging,