A system that oscillates with simple harmonic motion. The harmonic oscillator is exactly soluble in both classical mechanics and quantum mechanics. Many systems exist for which harmonic oscillators provide very good approximations. Atoms vibrating about their mean positions in molecules or crystal lattices at low temperatures can be regarded as good approximations to harmonic oscillators in quantum mechanics. Even if a system is not exactly a harmonic oscillator the solution of the harmonic oscillator is frequently a useful starting point for treating such systems using perturbation theory. Compare anharmonic oscillator.
Subjects: Chemistry — Physics.