Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Artificial Material with Negative Thermal Expansion: A Simple
  Geometrical Approach   In the paper we report the modeling and design of material which has a
negative thermal expansion (NTE). The basic assumption is a potential between
the atoms in the material can be approximated by a Lennard-Jones potential
(6-12) and the dominant interaction is only between nearest neighbors. We show
that the material formed by alternating atomic layers wherein each layer
contains a type of atom, and geometry of the arrangement of atoms is
triangular, may experience an NTE when sigma_AA = sigma_BB = sigma_AB,
epsilon_AA = epsilon_BB < epsilon_AB/4 are satisfied, where sigma_ij and
epsilon_ij are Lennard-Jones parameters

8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an