Calculation of Fine-Structure Splittings and Quadrupole Antishielding Factors for Atomic States

As a test of accurate valence wave functions which have been previously obtained for the excited np states of the alkali atoms, we have calculated the fine-structure splittings Δν using these wave functions. The resulting values of Δνₜₕₑₒᵣ are generally in good agreement with the corresponding experimental values Δνₑₓₚₜ. Calculations have also been carried out for the atomic quadrupole shielding factor R for the ground states of boron (B 2p) and aluminum (Al 3p), and the ionic antishielding factor γ_∞ for the ions B⁺, Al⁺, and Al³⁺. The value of R(B 2p)=+0.048 is in good agreement with the results of calculations using spin-polarization wave functions. The result for R(Al 3p)=-0.063 leads to a corrected value of the nuclear quadrupole moment Q(Al²⁷)=0.140±0.002 b, using the atomic-beam result of Lew and Wessel. The ionic antishielding factors γ_∞ have the following calculated values: γ_∞(B⁺)=+0.773, γ_∞(Al⁺)=-1.68, and γ_∞(Al³⁺)-2.4.