In the area of solid state chemistry. graphite intercalation compounds are materials prepared by intercalation of diverse guests into graphite.  The materials have the formula (guest)C where n can range from 8 to 40's.  The distance between the carbon layers increases significantly upon insertion of the guests.   Common guests are reducing agents such as alkali metals.  Strong oxidants, such as arsenic pentafluoride also intercalate into graphite. Intercalation involves electron transfer into or out of the host.  The properties of these materials differ from those of the parent graphite.