Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological Dirac Semimetal Phase in Bismuth Based Anode Materials for
  Sodium-Ion Batteries   Bismuth has recently attracted interest in connection with Na-ion battery
anodes due to its high volumetric capacity. It reacts with Na to form Na$_3$Bi
which is a prototypical Dirac semimetal with a nontrivial electronic structure.
Density-functional-theory based first-principles calculations are playing a key
role in understanding the fascinating electronic structure of Na$_3$Bi and
other topological materials. In particular, the
strongly-constrained-and-appropriately-normed (SCAN)
meta-generalized-gradient-approximation (meta-GGA) has shown significant
improvement over the widely used generalized-gradient-approximation (GGA)
scheme in capturing energetic, structural, and electronic properties of many
classes of materials. Here, we discuss the electronic structure of Na$_3$Bi
within the SCAN framework and show that the resulting Fermi velocities and {\it
s}-band shift around the $\Gamma$ point are in better agreement with
experiments than the corresponding GGA predictions. SCAN yields a purely
spin-orbit-coupling (SOC) driven Dirac semimetal state in Na$_3$Bi in contrast
with the earlier GGA results. Our analysis reveals the presence of a
topological phase transition from the Dirac semimetal to a trivial band
insulator phase in Na$_{3}$Bi$_{x}$Sb$_{1-x}$ alloys as the strength of the SOC
varies with Sb content, and gives insight into the role of the SOC in
modulating conduction properties of Na$_3$Bi.

16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas