Square barrier model of a one-dimensional inhomogeneous electron liquid in relation to relativistic density functional theory

A long-term objective of density functional theory (DFT) has been to obtain the electronic kinetic energy density directly from the ground-state density, without recourse to wave functions. This is the more important in relativistic DFT since Dirac wave functions have four components. The above aim is here achieved for the admittedly specialized square barrier model of a one-dimensional inhomogeneous electron liquid. (author)