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A new carbon allotrope with six-fold helical chains in all-sp2 bonding networks.

ABSTRACT: Using a recently developed approach to constructing covalent network structures from linear carbyne, we identify by ab initio calculations a new carbon allotrope in R3m (D(3d)(5) symmetry that comprises six-fold helical chains with alternating sp(2)-type single and double bonds along the chains that are connected via zigzag benzene rings. This 6-fold carbene is characterized as a three-dimensional three-connected chiral crystalline modification of graphite. Phonon and electronic band calculations indicate that this new structure is dynamically stable and is a semiconductor with a band gap of 0.47 eV, in contrast to the semimetallic nature of graphite. Simulated x-ray diffraction patterns of the 6-fold carbene provide an excellent match to the previously unexplained distinct diffraction peak of a new carbon allotrope found in recent detonation experiments. These results establish a new carbon phase and offer insights into its outstanding structural and electronic properties.

SUBMITTER: Wang JT

PROVIDER: S-EPMC3949244 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature

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A new carbon allotrope with six-fold helical chains in all-sp2 bonding networks.

Wang Jian-Tao JT Chen Changfeng C Wang Enge E Kawazoe Yoshiyuki Y

Scientific reports 20140311

Using a recently developed approach to constructing covalent network structures from linear carbyne, we identify by ab initio calculations a new carbon allotrope in R3m (D(3d)(5) symmetry that comprises six-fold helical chains with alternating sp(2)-type single and double bonds along the chains that are connected via zigzag benzene rings. This 6-fold carbene is characterized as a three-dimensional three-connected chiral crystalline modification of graphite. Phonon and electronic band calculation ...[more]

PMID: 24614093

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