An allotropic form of the element carbon consisting of layers of hexagonally arranged carbon atoms in a planar condensed ring system @[email protected] The layers are stacked parallel to each other in a three-dimensional crystalline long-range order. There are two allotropic forms with different stacking arrangements, hexagonal and rhombohedral. The chemical bonds within the layers are covalent with \(\text{sp}^{2}\) @[email protected] and with a C–C distance of \(141.7\ \text{pm}\). The weak bonds between the layers are metallic with a strength comparable to van der Waals bonding only.
The term graphite is also used often but incorrectly to describe @[email protected], i.e. materials consisting of @[email protected] made from carbon materials by processing to temperatures greater than \(2500\ \text{K}\), even though no perfect graphite structure is present.
PAC, 1995, 67, 473. (Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)) on page 491 [Terms] [Paper]