This book is on approximation methods and applications of Quantal Density Functional Theory
(QDFT) a new local effective-potential-energy theory of electronic structure. What
distinguishes the theory from traditional density functional theory is that the electron
correlations due to the Pauli exclusion principle Coulomb repulsion and the correlation
contribution to the kinetic energy - the Correlation-Kinetic effects - are separately and
explicitly defined. As such it is possible to study each property of interest as a function of
the different electron correlations. Approximations methods based on the incorporation of
different electron correlations as well as a many-body perturbation theory within the context
of QDFT are developed. The applications are to the few-electron inhomogeneous electron gas
systems in atoms and molecules as well as to the many-electron inhomogeneity at metallic
surfaces.
