X‐ray and Auger transitions in atoms and ions

Theoretical calculations of x‐ray and Auger transition rates for atoms based on independent‐particle models and for highly‐charged ions using the multiconfiguration Dirac‐Fock method are reviewed. The deficiency of the independent‐particle model is discussed. Effects of relativity, intermediate coupling and configuration interaction on the transition rates are examined. For the highly‐charged ions with many‐open shells, the trends of Auger rates and oscillator strengths along an isoelectronic sequence are strongly perturbed by the frequent occurrences of level crossings. Care should be taken in identifying the level crossings when using the isoelectronic interpolation or extrapolation to obtain the transition rates.