  Up to now, many guest atoms/molecules/ions have been successfully synthesized
into graphite to form the various compounds. For example, alkali-atom graphite
intercalation compounds are verified to reveal the stage-n structures,
including LiC6n and LiM8n [M=K. Rb and Cs; n=1, 2, 3; 4]. On the other side,
AlCl4-ion/molecule ones are examined to show stage-4 and stage-3 cases at room
and lower temperatures, respectively. Stage-1 and stage-2 configurations, with
the higher intercalant concentrations, are unable to synthesize in experimental
laboratories. This might arise from the fact that it is quite difficult to
build the periodical arrangements along the longitudinal z and transverse
directions simultaneously for the large ions or molecules. Our works are mainly
focused on stage-1 and stage-2 systems in terms of geometric and electronic
properties. The critical features, being associated with the atom-dominated
energy spectra and wave function within the specific energy ranges, the active
multi-orbital hybridization in distinct chemical bonds, and atom- &
orbital-decomposed van Hove singularities, will be thoroughly clarified by the
delicate simulations and analyses.
