Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strength of correlations in pnictides and its assessment by theoretical
  calculations and spectroscopy experiments   LDA+DMFT (Local Density Approximation combined with Dynamical Mean-Field
Theory) computation scheme has been used to calculate spectral properties of
LaFeAsO -- the parent compound of the new high-T_c iron oxypnictides. The
average Coulomb repulsion U=3-4 eV and Hund's exchange J=0.8 eV parameters for
iron 3d electrons were calculated using the first principles constrained
density functional theory scheme in the Wannier functions formalism. DMFT
calculations using these parameters result in moderately correlated electronic
structure with effective electron mass enhancement m^*~2 that is in agreement
with the experimental X-ray and photoemission spectra. Conclusion of moderate
correlations strength is confirmed by the observation that pnictides
experimental spectra agree well with corresponding spectra for metallic iron
while being very different with Mott insulator FeO spectra.

10
The categories of this paper are: q-bio
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con