  The phonon dispersion unfolding method is useful for obtaining hidden Bloch
symmetries and comparing theoretical results with experiment spectrums (e.g.,
inelastic neutron scattering, inelastic X-ray scattering, Raman). In this
paper, we propose a method to unfold phonon dispersions. The main advantage of
this method is the ability to handle systems with heavy breaking of spatial
translational symmetry. Its validity is tested by pure diamond, diamond with Si
substitution, and diamond with C vacancies.
