  We derive and employ a local potential to represent the Fock exchange
operator in electronic single-particle equations. This local Fock-exchange
(LFX) potential is very similar to the exact exchange (EXX) potential in
density functional theory (DFT). The practical software implementation of the
two potentials (LFX and EXX) yields robust and accurate results for a variety
of systems (semiconductors, transition metal oxides) where Hartree Fock and
popular approximations of DFT typically fail. This includes examples
traditionally considered qualitatively inaccessible to calculations that omit
correlation.
