Qian Wang, Peking University, Beijing, China, and colleagues have proved theoretically that penta-graphene – a thin 2D sheet composed of carbon pentagons – is dynamically, thermally, and mechanically stable.

The simulations suggest that this carbon polymorph can withstand temperatures as high as 1000 K, has an unusual negative Poisson’s ratio and an ultrahigh ideal strength due to its unique atomic configuration, as well as a large band gap. Penta-graphene can be scaled off from T12-carbon and rolled up to form pentagon-based semiconductive nanotubes.

Penta-graphene is expected to have applications in electronics, biomedicine, nanotechnology. However, the next step is to synthesize it.

• Penta-graphene: A new carbon allotrope,
  Shunhong Zhang, Jian Zhou, Qian Wang, Xiaoshuang Chen, Yoshiyuki Kawazoe, Puru Jena,
  Proc. Nat. Acad. Sci. 2015.
  DOI: 10.1073/pnas.1416591112