Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: $H_2$ and $(H_2)_2$ molecules with an ab initio optimization of wave
  functions in correlated state: Electron-proton couplings and intermolecular
  microscopic parameters   The hydrogen molecules $H_2$ and $(H_2)_2$ are analyzed with electronic
correlations taken into account between the $1s$ electrons exactly. The optimal
single-particle Slater orbitals are evaluated in the correlated state of $H_2$
by combining their variational determination with the diagonalization of the
full Hamiltonian in the second-quantization language. All electron--ion
coupling constants are determined explicitly and their relative importance is
discussed. Sizable zero-point motion amplitude and the corresponding energy are
then evaluated by taking into account the anharmonic contributions up to the
ninth order in the relative displacement of the ions from their static
equilibrium value. The applicability of the model to the solid molecular
hydrogen is briefly analyzed by calculating intermolecular microscopic
parameters for $2 \times H_2$ rectangular configurations.

10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
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The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics