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Register a new userMulti-configuration Dirac-Hartree-Fock calculations of excitation energies, oscillator strengths and hyperfine structure constants for low-lying levels of Sm I
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The multi-configuration Dirac-Hartree-Fock method was employed to calculate the total and excitation energies, oscillator strengths and hyperfine structure constants for low-lying levels of Sm I. In the first-order perturbation approximation, we systematically analyzed correlation effects from each electrons and electron pairs. It was found that the core correlations are of importance for physical quantities concerned. Based on the analysis, the important configuration state wave functions were selected to constitute atomic state wave functions. By using this computational model, our excitation energies, oscillator strengths, and hyperfine structure constants are in better agreement with experimental values than earlier theoretical works.
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We have investigated energies, magnetic dipole hyperfine structure constants ($A_{hyf}$) and electric dipole (E1) matrix elements of a number of low-lying states of the triply ionized tin (Sn$^{3+}$) by employing relativistic coupled-cluster theory. Contributions from the Breit interaction and lower-order quantum electrodynamics (QED) effects in determination of above quantities are also given explicitly. These higher-order relativistic effects are found to be important for accurate evaluation of energies, while QED contributions are seen to be contributing significantly to the determination of $A_{hyf}$ values. Our theoretical results for energies are in agreement with one of the measurements but show significant differences for some states with another measurement. Reported $A_{hyf}$ will be useful in guiding measurements of hyperfine levels in the stable isotopes of Sn$^{3+}$. The calculated E1 matrix elements are further used to estimate oscillator strengths, transition probabilities and dipole polarizabilities ($alpha$) of many states. Large discrepancies between present results and previous calculations of oscillator strengths and transition probabilities are observed for a number of states. The estimated $alpha$ values will be useful for carrying out high precision measurements using Sn$^{3+}$ ion in future experiments.
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