Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Al20+ does melt, albeit above the bulk melting temperature of aluminium
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex