Nonexcited

Nonexcited is an adjective used in physics and chemistry to describe a system, particle, or state that is not in an excited condition. In atomic and molecular contexts, an excited state has higher energy than the ground state; a nonexcited state typically refers to the ground state or another low-energy condition that has not been promoted by external energy input. In spectroscopy and photophysics, samples may be described as nonexcited before irradiation or after relaxation when they have returned to the ground state.

In electronic terms, nonexcited often means that electrons occupy the lowest available energy levels, and optical or chemical processes involve transitions from that ground state to higher energies. Some discussions also distinguish vibrational or rotational nonexcited states, such as a molecule being in its vibrational ground state. At finite temperatures, a population can exist in excited levels, but the designation nonexcited usually emphasizes the dominant ground-state condition or the specific interest in transitions from the ground state.

Usage and terminology notes: nonexcited is less common in everyday language and is often replaced by more precise terms such as ground state or unexcited when referring to electronic structure. The form non-excited or nonexcited may appear in different texts; however, clarity is improved by specifying the type of excitation (electronic, vibrational, rotational) and the relevant energy levels.

See also: ground state, excitation, energy level, spectroscopy.