Method of local‐scaling transformations and density functional theory in quantum chemistry. III. The energy density functional: Spin‐restricted approach

The rigorous derivation of the energy density functional is proposed within the framework of the spinfree, or spin‐restricted formulation of the energy density functional theory. It is shown particularly that the kinetic energy density functional is given by a sum of the Weizsacker term and the so‐called “modified” Thomas–Fermi one. The variational principle is formulated for the energy density functional theory in terms of the Euler–Lagrange equation, and the virial theorem is proposed.