Interaction between3dand3sElectrons in the Second Spectra of the Iron Group

Abstract

Six hundred and fifty levels of the low even configurations of the second spectra of the iron group are calculated. The values of the parameters appearing in the theoretical formulas are determined by comparison with 408 experimental levels. The use of interpolation formulas for the parameters reduces their number to 46, which makes the results very reliable. The introduction of the interaction between $3d$ and $3s$ electrons, and the $Q$ correction reduces the mean error from 230 ${\mathrm{cm}}^{-1\mathrm{}}$ to 115 ${\mathrm{cm}}^{-1\mathrm{}}$, which is 0.12% of the experimental range. The special role of the interaction between configurations having the same set of principal quantum numbers is discussed.