Figure 2.

Dependence of the individual orbital spin-orbit coupling strength λ_nl for atoms as a function of their atomic number Z Calculated results [Herman and Skillman, 1963] using the Hartree-Fock method (solid colored lines) are compared to the hydrogenic Z⁴ dependence, which is computed for the 3d series (upper dashed line). For the outermost electrons (indicated by the circles and the shaded area), which are the relevant electrons in the solid, the quantum numbers n, l change with Z and the spin-orbit interaction increases much more slowly, following roughly the Landau-Lifshitz Z² scaling (lower dashed line), although within each series, the dependence remains closer to Z⁴. Adapted from [Shanavas et al., 2014].