  Current-density-functional theory is used to perturbatively calculate
single-particle energies of open-shell atoms prepared in a current-carrying
state. We focus on the highest occupied such energy, because its negative is,
in principle, the exact ionization energy. A variety of different density
functionals and calculational schemes are compared with each other and
experiment. When the atom is prepared in a current-carrying state, a
current-dependent exchange-correlation functional is found to slightly lower
the single-particle energy of the current-carrying orbital, as compared to a
calculation using standard (current independent) density functionals for the
same system. The current-dependent terms in the exchange-correlation functional
thus provide additional stabilization of the current-carrying state.
