Phagraphene () is a proposed

graphene Graphene () is a carbon allotrope consisting of a Single-layer materials, single layer of atoms arranged in a hexagonal lattice, honeycomb planar nanostructure. The name "graphene" is derived from "graphite" and the suffix -ene, indicating ...

allotrope Allotropy or allotropism () is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of the elements. Allotropes are different structural modifications of an element: the ...

composed of 5-6-7 carbon rings. Phagraphene was proposed in 2015 based on systematic evolutionary structure searching. Theoretical calculations showed that phagraphene is not only dynamically and thermally stable, but also has distorted

Dirac cone In physics, Dirac cones are features that occur in some electronic band structures that describe unusual electron transport properties of materials like graphene and topological insulators. In these materials, at energies near the Fermi leve ...

s. The direction-dependent cones are robust against external strain with tuneable Fermi velocities. Higher-energy allotropes named Haeckelite contained penta- hexa- and hepta-carbon rings. Three types (rectangular, oblique and hexagonal) were proposed as early as 2000. These metastable allotropes have a trivial intrinsic metallic behavior. Phagraphene is predicted to have a

potential energy In physics, potential energy is the energy of an object or system due to the body's position relative to other objects, or the configuration of its particles. The energy is equal to the work done against any restoring forces, such as gravity ...

of 193.2

kcal KCAL may refer to: * KCAL (AM), a radio station (1410 AM) licensed to Redlands, California, United States * KCAL-FM, a radio station (96.7 FM) licensed to Redlands, California, United States *KCAL-TV KCAL-TV (channel 9) is an independent tel ...

/ mol. The

bond order In chemistry, bond order is a formal measure of the multiplicity of a covalent bond between two atoms. As introduced by Gerhard Herzberg, building off of work by R. S. Mulliken and Friedrich Hund, bond order is defined as the difference between t ...

is 1.33, the same as for graphene.

PHA/graphene

An unrelated material called PHA/graphene is a

polyhydroxyalkanoate Polyhydroxyalkanoates or PHAs are polyesters produced in nature by numerous microorganisms, including through bacterial fermentation of sugars or lipids. When produced by bacteria they serve as both a source of energy and as a carbon store. More ...

graphene composite.

References

{{Reflist, 2 Graphene Allotropes of carbon