Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-pressure molecular phases of solid carbon dioxide   We present a theoretical study of solid carbon dioxide up to 50GPa and 1500K
using first-principles calculations. In this pressure-temperature range,
interpretations of recent experiments have suggested the existence of CO2
phases which are intermediate between molecular and covalent-bonded solids. We
reexamine the concept of intermediate phases in the CO2 phase diagram and
propose instead molecular structures, which provide an excellent agreement with
measurements.

25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con