Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Wiener polarity index of benzenoid systems and nanotubes   In this paper, we consider a molecular descriptor called the Wiener polarity
index, which is defined as the number of unordered pairs of vertices at
distance three in a graph. Molecular descriptors play a fundamental role in
chemistry, materials engineering, and in drug design since they can be
correlated with a large number of physico-chemical properties of molecules. As
the main result, we develop a method for computing the Wiener polarity index
for two basic and most commonly studied families of molecular graphs, benzenoid
systems and carbon nanotubes. The obtained method is then used to find a closed
formula for the Wiener polarity index of any benzenoid system. Moreover, we
also compute this index for zig-zag and armchair nanotubes.

9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con