Multiconfiguration Dirac-Hartree-Fock theory for copper Kα and Kβ diagram lines, satellite spectra, and ab initio determination of single and double shake probabilities

Abstract

The x-ray spectra of copper Kα and Kβ remain a topic of great interest due to the complex open-shell processes involved, with many discrepancies among theories and experiments. We present high-accuracy theory of copper Kα and Kβ diagram and satellite spectra in the multiconfiguration Dirac-Hartree-Fock method. Diagram spectra are expanded to 5s with simultaneous convergence of 28 000 configuration state functions (CSFs) (Kα) and to 6g with simultaneous convergence of 91 000 CSFs (Kβ), achieving eigenvalue convergence to ±0.03 eV or 0.000 25%, approximately a factor of 10 improvement over past work. It is necessary to invoke biorthogonalization, developments of the active space approach, anal..