  The novel graphene allotropes $\alpha$-, $\beta$-, and $\gamma$-graphyne
derive from graphene by insertion of acetylenic groups. The three graphynes are
the only members of the graphyne family with the same hexagonal symmetry as
graphene itself, which has as a consequence similarity in their electronic and
vibrational properties. Here, we study the electronic band structure, phonon
dispersion, and Raman spectra of these graphynes within an
\textit{ab-initio}-based non-orthogonal tight-binding model. In particular, the
predicted Raman spectra exhibit a few intense resonant Raman lines, which can
be used for identification of the three graphynes by their Raman spectra for
future applications in nanoelectronics.
