Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First-principles study on atomic configuration of electron-beam
  irradiated C$_{60}$ clusters   A theoretical study proposes the atomic configuration of electron-beam
irradiated C$_{60}$ thin films. We examined the electronic structure and
electron-transport properties of the C$_{60}$ clusters using density-functional
calculations and found that a rhombohedral C$_{60}$ polymer with $sp^3$-bonded
dumbbell-shaped connections at the molecule junction is a semiconductor with a
narrow band gap while the polymer changes to exhibit metallic behavior by
forming $sp^2$-bonded peanut-shaped connections. Conductance below the Fermi
level increases and the peak of the conductance spectrum arising from the
$t_{u1}$ states of a C$_{60}$ molecule becomes obscure after the connections
are rearranged. The present rohmbohedral film, including the [2+2]
four-membered rings and peanut-shaped connections, is a candidate to represent
the structure of the metallic C$_{60}$ polymer at the initial stage of
electron-beam irradiation.

9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ