Coulomb term U and 5f electron excitation energies for the metals actinium to berkelium
J F. Herbst, R E. Watson
Relativistic Hartree-Fock-Wigner-Seitz band calculations have been performed for the actinide metals Ac through Bk in order to estimate the Coulomb term U and 5 f electron excitation energies. Our calculations predict that the tetravalent state (four 6 d-7 s conduction electrons) is stable relative to the trivalent state for the lighter elements and that near uranium relative stabilization of the trivalent state occurs. We find that U increases from 2-3 eV for Th to 4-5 eV for the heavier elements considered. 5 f level widths W are estimated and found to decrease from 2 to 1/2 eV; together with the results for U this points to progressive localization of the 5f states. The ratio U/W, which is most indicative of localization, takes on values intermediate between those for 3d and 4f electrons.
Physical Review B (Condensed Matter and Materials Physics)
and Watson, R.
Coulomb term U and 5f electron excitation energies for the metals actinium to berkelium, Physical Review B (Condensed Matter and Materials Physics)
(Accessed June 10, 2023)