Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chemical and Lattice Stability of the Tin Sulfides   The tin sulfides represent a materials platform for earth-abundant
semiconductor technologies. We present a first-principles study of the five
known and proposed phases of SnS together with SnS2 and Sn2S3. Lattice-dynamics
techniques are used to evaluate the dynamical stability and
temperature-dependent thermodynamic free energy, and we also consider the
effect of dispersion forces on the energetics. The recently identified
{\pi}-cubic phase of SnS is found to be metastable with respect to the
well-known orthorhombic Pnma/Cmcm equilibrium. The Cmcm phase is a low-lying
saddle point between Pnma minima on the potential-energy surface, and is
observed as an average structure at high temperatures. Bulk rocksalt and
zincblende phases are found to be dynamically unstable, and we show that
whereas rocksalt SnS can potentially be stabilised under a reduction of the
lattice constant, the hypothetical zincblende phase proposed in several earlier
studies is extremely unlikely to form. We also investigate the stability of
Sn2S3 with respect to SnS and SnS2, and find that both dispersion forces and
vibrational contributions to the free energy are required to explain its
experimentally-observed resistance to decomposition.

18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio