Relativistic Calculations for Be-like Iron

Relativistic configuration interaction calculations for the states of 1s22s2, 1s22s3l (l = s,p,d) and 1s22p3l (l = s,p,d) configurations of iron are carried out using relativistic configuration interaction (RCI) and multi-configuration Dirac–Fock (MCDF) method in the active interaction approach. In the present calculation, a large-scale configuration expansion was used in describing the target states. These results are extensively compared with other available calculative and experimental and observed values, the corresponding present results are in good agreement with experimental and observed values, and some differences are found with other available calculative values. Because more relativistic effects are considered than before, the present results should be more accurate and reliable.