Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pressure-induced Phonon Softenings and the Structural and Magnetic
  Transitions in CrO$_{2}$   To investigate the pressure-induced structural transitions of chromium
dioxide (CrO$_{2}$), phonon dispersions and total energy band structures are
calculated as a function of pressure. The first structural transition has been
confirmed at P$\approx$ 10 GPa from the ground state tetragonal CrO$_{2}$
(t-CrO$_{2}$) of rutile type to orthorhombic CrO$_{2}$ (o-CrO$_{2}$) of
CaCl$_{2}$ type. The half-metallic property is found to be preserved in
o-CrO$_{2}$. The softening of Raman-active B$_{1g}$ phonon mode, which is
responsible for this structural transition, is demonstrated. The second
structural transition is found to occur for P$\geq$ 61.1 GPa from ferromagnetic
(FM) o-CrO$_{2}$ to nonmagnetic (NM) monoclinic CrO$_{2}$ (m-CrO$_{2}$) of
MoO$_{2}$ type, which is related to the softening mode at {\bf q} =
R(1/2,0,1/2). The third structural transition has been newly identified at P=
88.8 GPa from m-CrO$_{2}$ to cubic CrO$_{2}$ of CaF$_{2}$ type that is a FM
insulator.

21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
19
The categories of this paper are: eess
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph