title: Translation symmetry breakdown in low-dimensional lattices of pentagonal rings.
abstract: The mechanism of translation symmetry breakdown in newly proposed low-dimensional carbon pentagon-constituted nanostructures (e.g., pentagraphene) with multiple sp(2)/sp(3) sublattices was studied by GGA DFT, DFTB, and model potential approaches. It was found that finite nanoclusters suffer strong uniform unit cell bending followed by breaking of crystalline lattice linear translation invariance caused by structural mechanical stress. It was shown that 2D sp(2)/sp(3) nanostructures are correlated transition states between two symmetrically equivalent bent structures. At DFT level of theory the distortion energy of the flakes (7.5 × 10(-2) eV/atom) is much higher the energy of dynamical stabilization of graphene. Strong mechanical stress prevents stabilization of the nanoclusters on any type of supports by either van der Waals or covalent bonding and should lead to formation of pentatubes, nanorings, or nanofoams rather than infinite nanoribbons or nanosheets. Formation of two-layered pentagraphene structures leads to compensation of the stress and stabilization of flat finite pentaflakes.
authors.affiliation: Department of Chemistry and Green-Nano Materials Research Center, College of Natural Sciences, Kyungpook National University , 1370 Sankyuk-dong, Buk-gu, Daegu 702-701, Republic of Korea.
authors.forename: Paul
authors.initials: P
authors.lastname: Avramov
authors.affiliation: N.M.Emanuel Institute of Biochemical Physics, Russian Academy of Sciences , Kosugin 4, 119334 Moscow, Russia.
authors.forename: Victor
authors.initials: V
authors.lastname: Demin
authors.affiliation: Department of Materials Science and NanoEnigeering, Rice University , Houston, Texas 77005, United States.
authors.forename: Ming
authors.initials: M
authors.lastname: Luo
authors.affiliation: Department of Chemistry and Green-Nano Materials Research Center, College of Natural Sciences, Kyungpook National University , 1370 Sankyuk-dong, Buk-gu, Daegu 702-701, Republic of Korea.
authors.forename: Cheol Ho
authors.initials: CH
authors.lastname: Choi
authors.affiliation: National University of Science and Technology MISiS , Moscow 119049, Russian Federation.
authors.forename: Pavel B
authors.initials: PB
authors.lastname: Sorokin
authors.affiliation: Department of Materials Science and NanoEnigeering, Rice University , Houston, Texas 77005, United States.
authors.forename: Boris
authors.initials: B
authors.lastname: Yakobson
authors.affiliation: N.M.Emanuel Institute of Biochemical Physics, Russian Academy of Sciences , Kosugin 4, 119334 Moscow, Russia.
authors.forename: Leonid
authors.initials: L
authors.lastname: Chernozatonskii
keywords: correlated diabatic transition state; corrugation; linear translation invariance; mechanical stress; pentagon-constituted nanostructures; pentagraphene