Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Stability of Endohedral Rare Gas Fullerenes   The stability of Ne@C$_{60}$ and He@C$_{60}$ is discussed in the context of a
spherical model where the carbon atoms are smeared out into a uniform shell.
The electronic properties of the sixty $\pi$ electrons together with those of
the central atom are treated in the Thomas-Fermi approximation. Simple
electrostatic reasoning elucidates the nature of the radial stability of the
complex. A method to include non-spherical corrections is outlined. Possible
bonding topologies of the central atom and the C$_{60}$ cage are discussed, as
well as the relevance of these topologies to incipient central atom
distortions.

23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg