Density functional theory of interacting closed shell systems. II. The determination of charge densities and the Hellmanndash;Feynman theorem

摘要

The density functional formalism and the additive density approximation are used to obtain the nonadditive contribution to the electron density of a set of closed shell atoms in the absence of external fields. It is shown that due to the additive density approximation, the Hellmanndash;Feynman theorem is violated when the force on the nucleus is examined. The reason for this violation is discussed.