Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamics and Thermodynamics of a Novel Phase of NaAlH4   We characterize a novel orthorhombic phase (gamma) of NaAlH4, discovered
using first-principles molecular dynamics, and discuss its relevance to the
dehydrogenation mechanism. This phase is close in energy to the known
low-temperature structure and becomes the stabler phase above 320 K, thanks to
a larger vibrational entropy associated with AlH4 rotational modes. The
structural similarity of gamma-NaAlH4 to alpha-Na3AlH6 suggests it acts as a
key intermediate during hydrogen release. Findings are consistent with recent
experiments recording an unknown phase during dehydrogenation.

34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
2
The categories of this paper are: math