Relativistic spin-polarized electronic structure of Ce and Pu

The first fully relativistic calculations that also include spin polarization are presented for the single-site t matrix for Ce and Pu. The pattern of resonant energies for Ce are compared to recent atomic eigenvalue results for the Ce³⁺ ion. The Ce band states are also determined along the 〈100〉 and 〈111〉 directions in the Brillouin zone by solving the Dirac equation with an internal magnetic field constructed from scalar relativistic linear muffin-tin orbital (LMTO) spin-polarized calculations. In the relativistic case the coupling between spin-orbit and spin-polarization interactions destroys rotational symmetry, unlike in the nonrelativistic spin-polarized formalism, and hence leads to completely nondegenerate f and d states in these systems (similar to the Zeeman effect). To see this we also give results for an applied magnetic field that only couples to the spins and hence resembles an effective internal spin-polarized field.