Ionization potentials relativistic changes

Keywords Relativistic effects Infinite-order Two-component theory Change of picture Back unitary transformation Ionization potentials Electron affinities Dissociation energies Hydrolysis Electric properties CEBE Strong bonds to gold... 

Differences in lanthanide and actinide hydration thermodynamics have been discussed by Bratsch and Lagowski (1986) who attributed the difierences to relativistic effects in the actinides which cause changes in the energies of the s, p, d, and f orbitals. For example, the first and second ionization potentials of the electrons of the 7s state of the actinides are higher than those of the 6s state of the lanthanides whereas the third ionization potentials are similar for both families and the fourth ionization potential is lower for the actinides than the lanthanides. The small decrease in IP3 and IP4 for the f configuration in the actinides results in smooth variations in the relative stabilities of the adjacent oxidation states across the actinide series while the greater spatial extension of the 5f orbitals increases the actinide susceptibility to environmental efiects (Johnson 1982). 

Figure 1 Relativistic changes in the ionization potentials (logarithmic scale, in 10"> eV y = log,Q Ar ) for H-like atoms (Z = 1-137) for several s states (n = 1-7), The curves for the s states are shown in the order Ar ( s) > Ar (( - - 1)s)...

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