Determination of empirical configuration parameters from experimental data in l^4l+1l' electron configurations: Application to Ar I 3p ⁵4s, 3p⁵4p and 3p⁵3d

It is shown that experimental oscillator strengths or Lande g values of a small number of energy levels may be used to obtain certain of the Slater-Condon parameters of l^4l+1l' electron configurations which may be used to predict a large number of the other energy levels. The analysis uses deduced values of eigenvector expansion coefficients for LS-coupled basis functions to transform the diagonal energy level matrix into a numerical LS Hamiltonian matrix. Equating this with the analytical Hamiltonian leads to simultaneous equations in the configuration parameters. The method is tested in three Ar I 3p⁵nl configurations with satisfactory results. In the case of Ar I 3p⁵₄d it is found that the introduction of an additional empirical electrostatic parameter leads to a substantially improved energy level fit. This parameter effectively takes into account the LS dependence of ³F Slater integrals.