THE LOCAL ORBITAL ENERGY AND DENSITY FUNCTIONAL THEORY

From the viewpoint of density functional theory, an expression is derived which improves the average energy of a trial density. Applications to atoms and molecules are made using wave function methods and are based on properties of the variance, which is defined as \documentclass{article}\pagestyle{empty}\begin{document}$ (\overline {\varepsilon ^2 } - (\overline \varepsilon)^2)^{1/2} $\end{document}, where ϵ is the local orbital energy. Calculated results for both Hartree‐Fock and correlated wave functions are quite encouraging. Copyright © 1990 John Wiley & Sons, Inc.