Quasirelativistic formulation of the quantum-defect-orbital method

Abstract

The quantum-defect-orbital method has been reformulated in order to include a major part of the relativistic effects. The resulting quasirelativistic approach retains the simplicity of the original formulation but leads to more reliable results, particularly for the highly ionized atoms. The theory is illustrated by a series of calculations of oscillator strengths for the resonance transitions in atoms of lithium, sodium, and copper isoelectronic sequences.