Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dense superconducting phases of copper-bismuth at high pressure   Although copper and bismuth do not form any compounds at ambient conditions,
two intermetallics, CuBi and Cu$_{11}$Bi$_7$, were recently synthesized at high
pressures. Here we report on the discovery of additional copper-bismuth phases
at elevated pressures with high-densities from ab initio calculations. In
particular, a Cu$_2$Bi compound is found to be thermodynamically stable at
pressures above 59 GPa, crystallizing in the cubic Laves structure. In strong
contrast to Cu$_{11}$Bi$_7$ and CuBi, cubic Cu$_2$Bi does not exhibit any voids
or channels. Since the bismuth lone pairs in cubic Cu$_2$Bi are
stereochemically inactive, the constituent elements can be closely packed and a
high density of 10.52 g/cm$^{3}$ at 0 GPa is achieved. The moderate
electron-phonon coupling of $\lambda=0.68$ leads to a superconducting
temperature of 2 K, which exceeds the values observed both in
Cu$_{11}$Bi$_7$and CuBi, as well as in elemental Cu and Bi .

36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys