  The Dirac exchange interaction is derived from recent quantum kinetic theory
for collisionless plasmas. For this purpose, the kinetic equation is written in
the semiclassical and long wavelength approximations. The validity of the model
for real systems is worked out, in terms of temperature and density parameters.
Within the region of applicability, the correlation potential energy is shown
to be always smaller than the exchange contribution. From the moments of the
quantum kinetic equations, macroscopic, hydrodynamic equations are found, for
an electron-ion plasma. The Dirac exchange term is explicitly derived, in the
case of a completely degenerate electron gas. These results show, within
quantum kinetic theory for charged particle systems, a new view of the Dirac
exchange interaction frequently used in density functional theory
parametrization. Finally, a simpler form of the quantum plasma exchange kinetic
theory is also found.
