  The relative merits of current-spin-density- and spin-density-functional
theory are investigated for solids treated within the exact-exchange-only
approximation. Spin-orbit splittings and orbital magnetic moments are
determined at zero external magnetic field. We find that for magnetic (Fe, Co
and Ni) and non-magnetic (Si and Ge) solids, the exact-exchange
current-spin-density functional approach does not significantly improve the
accuracy of the corresponding spin-density functional results.
