Corrected atomic limit in the local-density approximation and the electronic structure of<i>d</i>impurities in Rb

We propose an energy functional for localized electron systems that corresponds to the constrained-local-density approximation (LDA) but includes some corrections for spin and orbital polarization to take Hund's first and second rules into account. The discontinuity of the one-electron potential known for an exact density functional can be easily incorporated in LDA in the scope of our formalism. Applications of the method to the electronic structure and configurational stability of d impurities in Rb are presented.