  The paper introduces a simple quantum model to calculate in a general way
allowed frequencies and energy levels of the anharmonic oscillator. The
theoretical basis of the approach has been introduced in two early papers aimed
to infer the properties of quantum systems exploiting the uncertainty principle
only. For clarity the anharmonic oscillator is described having in mind the
lattice oscillations of atoms/ions, yet quantum formalism of the model and
approach have general character and can be extended to any oscillating system.
The results show that the harmonic energy levels split into a complex system of
energy levels dependent upon the number of anharmonic terms that characterize
the oscillator.
