Precision calculations of atoms with few valence electrons
نویسنده
چکیده
We discuss the possibility of using pair-equations for the construction of the effective Hamiltonian H eff for valence electrons of an atom. The low-energy part of atomic spectrum is found by solving the eigenvalue problem for H eff. In this way it is possible to account efficiently for the valence-valence and core-valence correlations. We tested this method on a toy model of a four-electron atom with the core 1s 2. The spectrum obtained with H eff for two valence electrons is in a perfect agreement with the full configuration interaction for all four electrons.
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