The multi-configuration Dirac-Fock calculation of the low-lying levels of Sm

The excitation energies and hyper-fine structure constants of the low-lying levels of Sm atom are calculated using the multi-configuration Dirac-Fock (MCDF) method. The results show that the excitation energies of the ground state multiplets can be calculated accurately using a small orbital set but the higher levels need larger orbital sets. Similar inference can also be drawn from the discrepancy between the calculated values of the hyper-fine constants and the experimental data. A sequence of MCDF calculation demonst rates the effect of the MCDF potential on the orbitals. Among the rare eart h atoms Sm is a promising candidate for discrete symmetry violation experim ents in atoms. This makes accurate theoretical calculations necessary since parameters in particle physics can be derived by combining the experimenta l results with the theoretical results. And these could be a probe for the physics beyond the standard model.