Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electronic energy gap closure and metal-insulator transition in dense
  liquid hydrogen   Using Quantum Monte Carlo (QMC) calculations, we investigate the
insulator-metal transition observed in liquid hydrogen at high pressure. Below
the critical temperature of the transition from the molecular to the atomic
liquid, the fundamental electronic gap closure occurs abruptly, with a small
discontinuity reflecting the weak first-order transition in the thermodynamic
equation of state. Above the critical temperature, molecular dissociation sets
in while the gap is still open. When the gap closes, the decay of the
off-diagonal reduced density matrix shows that the liquid enters a gapless, but
localized phase: there is a cross-over between the insulating and the metallic
liquids. Compared to different DFT functionals, our QMC calculations provide
larger values for the fundamental gap and the electronic density of states
close to the band edges, indicating that optical properties from DFT
potentially benefit from error cancellations.

31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin