A Theoretical Investigation of the Configurations (3d + 4s)8 4p in Neutral Cobalt (Co I)

The Configurations 3d n 4p+3d n-14s4p+3d n-24s 24p in the First Spectra of the Iron Group

Energy levels and Lande g-factors for the configurations 3d ⁿ 4p+3d ^n-14s4p+3d ^n-24s ²4p in the first spectra of the iron group were calculated and compared with experimental values, in both general and individual treatments. The calculations were done in intermediate coupling taking into account explicity the interactions between configurations, as well as complete effective interactions of the core, and effective interactions d - p. Due to a successful starting point based on Hartree-Fock calculations for the Slater parameters, as well as the insertion of the effective interactions, considerable improvement was obtained compared to previous results. On fitting 1537 levels using 67 free interaction parameters a mean error of 182 cm^-1 was obtained. Altogether 3652 energy levels were calculated including all the levels for the configurations 3d ^n-24s ²4p across the sequence. It was shown that all interaction parameters could be expressed either as linear functions, or linear functions with small quadratic corrections, of the atomic number. There was general qualitative agreement between the values of the parameters calculated using the semi-empirical method and those calculated using Hartree-Fock methods. There remained some isolated terms with large deviations. These are attributed to be due to the interactions with the configurations (3d+4s) ⁿ 5p, that were not considered explicitly in this analysis. Tables comparing the experimental and calculated energy levels and Lande g-factors, as well as detailed analyses for each spectrum are given in another paper.

Odd Configurations in Neutral Nickel (Nil)

Experimental levels of the configurations 3d 94p, 3d 84s4p and 3d 95p of Ni I were compared with corresponding calculated values. The electrostatic interactions between the configurations (3d + 4s)94p as well as between 3d 84s4p and 3d 95p were considered explicitly. For the configurations (3d+4s)94p, 71 experimental levels were fitted by means of 17 free parameters to yield an rms error of 131 cm-1. On filling 83 levels of the configurations 3d 94p + 3d 84s4p + 3d 95p by means of 25 free parameters an rms error of 147 cm-1 was obtained.