Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Comment on "First-principles calculation of the superconducting
  transition in MgB2 within the anisotropic Eliashberg formalism"   Choi et al. [Phys. Rev. B 66, 020513 (2002)] recently presented first
principles calculations of the electron-phonon coupling and superconductivity
in MgB2, emphasizing the importance of anisotropy and anharmonicity. We point
out that (1) variation of the superconducting gap inside the sigma- or the
pi-bands can hardly be observed in real samples, and (2) taking the anisotropy
of the Coulomb repulsion into account influences the size of the small gap,
Delta_pi.

17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess