Theory of Strongly Correlated Electron Systems. III. Including   Correlation Effects into Electronic Structure Calculations
  In previous papers we showed that a division of the f-shell into two subsystems gives a better understanding of cohesive properties as well the general behavior of lanthanide systems. In this paper we present numerical computations using the suggested method. We show that the picture is consistent with most experimental data, e.g. the equilibrium volume and electronic structure in general. Compared to standard energy band calculations, or to calculations based on the self interaction correction and LDA+U, in the present approach f-(non-f)-mixing interaction is decreased by spectral weights of the many-body states of the f-ion are involved. 
U. Lundin, I. Sandalov, O. Eriksson