Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Kinetic energy densities based on the fourth order gradient expansion:
  performance in different classes of materials and improvement via machine
  learning
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess