Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pressure effect on the energy structure and superexchange interaction of
  the undoped orthorhombic La2CuO4: beyond the low-energy approximation   Using LDA+GTB multi-band approach, we studied the compression dependence of
the electronic structure and in-plane superexchange interaction J(P) in the
antiferromagnetic La214 at the 0% and 3% - hydrostatic and unaxial (along c
axial) compression. We obtained the superexchange interaction J(P=0)~0.15eV is
enhanced by ~20% under the 3% - hydrostatic compression and vice versa the J(P)
is decreased slightly by ~5,7% under the 3% - uniaxial compression. In both
cases the J(P) correlates with the in-plane hopping parameters and
dd-excitation energy \delta_s=e(^3B_{1})-e(A_{1})$ involving the the two-hole
states: Zhang-Rice singlet and ^3{B_{1}} triplet states. The spectral density
of the first removal states is a combined singlet-triplet character and a sign
of changes in the one with the pressure clearly reproduces the
\vec{k}-distribution of quasiparticle states with a different a_1- and
b_1-symmetry over the Brillouin zone as a whole.

10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics