After an atom or molecule absorbs a certain amount of energy, the electron is excited to a higher energy level but not yet ionized. Excited states generally refer to electronic excited states. The translational energy of molecules increases when gases are heated, and the vibrational energy of molecules increases when liquids and solids are heated, but no electrons are excited. These states are not excited states. When an atom or molecule is in an excited state, the distribution of the electron cloud will undergo certain changes, the equilibrium distance between the nuclei of the molecule increases slightly, and the chemical reaction activity increases. Excited State Computing