Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phagraphene: A Low-energy Graphene Allotrope composed of 5-6-7 Carbon
  Rings with Distorted Dirac Cones   Using systematic evolutionary structure searching we propose a new carbon
allotrope, phagraphene, standing for penta-hexa-hepta-graphene, because the
structure is composed of 5-6-7 carbon rings. This two-dimensional (2D) carbon
structure is lower in energy than most of the predicted 2D carbon allotropes
due to its sp2-hybridization and density of atomic packing comparable to
graphene. More interestingly, the electronic structure of phagraphene has
distorted Dirac cones. The direction-dependent cones are further proved to be
robust against external strain with tunable Fermi velocities.

31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th