ON THE "GENERALIZED SLATER" APPROXIMATION

We work within the Density Functional Theory (DFT), in the Local Density Approximation (LDA) with Self Interaction Correction (SIC). We show that, thanks to a formulation which employs two different sets of orbitals, the equations can be written in the form of eigenvalues equations, leading to single electron interpretation. However, the resulting hamiltonian is non-local. We propose to find it's best local approximation within using the Optimized Effective Potential (OEP) method. The resulting approximate theory is denominated "Generalized Slater". We show that this new scheme cures the pathologies of the standard SIC-Slater or SIC-KLI approximations.