The Chemical Entities of Biological Interest (ChEBI) ontology is downloaded weekly from EMBL-EBI at http://www.ebi.ac.uk/chebi/. The data is made available under the Creative Commons License (CC BY 3.0, http://creativecommons.org/licenses/by/3.0/). For more information see: Degtyarenko et al. (2008) ChEBI: a database and ontology for chemical entities of biological interest. Nucleic Acids Res. 36, D344–D350.
An allotropic form of the element carbon consisting of layers of hexagonally arranged carbon atoms in a planar condensed ring system (graphene layers). 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 sp(2) hybridization and with a C--C distance of 141.7 pm. The weak bonds between the layers are metallic with a strength comparable to van der Waals bonding only.
Synonyms:
related_synonym:
Cn; Formula=C; Graphit; SMILES=*:c1c(:*)c2c(:*)c(:*)c3c(:*)c4c(:*)c(:*)c(:*)c5c(:*)c(:*)c6c(:*)c(c1:*)c2c3c6c45.*:c1c(:*)c2c(:*)c(:*)c3c(:*)c4c(:*)c(:*)c(:*)c5c(:*)c(:*)c6c(:*)c(c1:*)c2c3c6c45.*:c1c(:*)c2c(:*)c(:*)c3c(:*)c4c(:*)c(:*)c(:*)c5c(:*)c(:*)c6c(:*)c(c1:*)c2c3c6c45.*:c1c(:*)c2c(:*)c(:*)c3c(:*)c4c(:*)c(:*)c(:*)c5c(:*)c(:*)c6c(:*)c(c1:*)c2c3c6c45; black lead; grafito; mineral carbon; plumbago