In graphite, carbon atoms in SP2 hybridization with layer forming Covalent bonds, each carbon atom with three Covalent bonds with three atoms attached. Six carbon atoms in the same plane, forming a six-the ring again and again, stretching into layers, where c-c bond lengths are 142pm, which belongs to the Atomic Crystal range of bond lengths, for the same level, therefore, it is an atomic crystal. Carbon atoms in the same plane also left a p orbital, they overlap. Electronic freedom or free electrons in metals, thermal and electrical conductivity of graphite, which is the metal crystal. Therefore as having a metal crystal.
Middle layer and layer of graphite Crystal 340pm between, distance, is based on the combined van der Waals force, which belongs to the molecular crystals between layers. However, because the carbon atoms are on the same plane, and extremely difficult to destroy, so is also very high melting point of graphite, stable chemical properties.
In view of its special way of bonding, must not be simply considered to be atomic Crystal crystals or molecules, according to the modern way of expression, that is a mixture of graphite crystal.