  Low-energy electronic properties of ABC-stacked graphite are studied by the
tight-binding model. There are linear and parabolic bands with and without
degeneracy. They show strongly anisotropic dispersions. ABC-stacked grahite is
a semimetal due to slight overlapping near the Fermi level beween conduction
and valence bands. The interlayer interactions could change the energy
dispersion, state degeneracy, and positions of band-crossing and band-edge
state. Density of states exhibit a shoulder structure, owing to band-edge
states near or at high symmetric points. Low-frequency Coulomb excitation
properties with different transferred momenta (${\bf q}'$s) are further studied
within the random phase approximation. The Landau dampings is too serious under
the parallel transferred momentum (${\bf q}\perp \hat z$); therefore, it is
impossible to observe the 3D optical plasmons. However, even for the
perpendicular transferred momentum (${\bf q}\parallel \hat z$), the full
assistance due to the thermal excitations is necessary to induce the collective
charge oscillations along the $z$-axis. The height and position of
temperature-induced plasmon peak in the energy loss spectrum are greatly
enhanced by the increasing temperature, but weakly depend on the various
transferred momenta. These features are very different from AA- and AB-stacked
graphites.
