  Using the optimized effective potential method in conjunction with the
semi-analytical approximation due to Krieger, Li and Iafrate, we have performed
fully self-consistent exact exchange-only density-functional calculations for
diatomic molecules with a fully numerical basis-set-free molecular code. The
results are very similar to the ones obtained with the Hartree Fock approach.
Furthermore we present results for ground states of positive atomic ions
including correlation contributions in the approximation of Colle and Salvetti.
It is found that the scheme performs significantly better than conventional
Kohn-Sham calculations.
