Electronic structure calculations and strong correlations: A model study



Metals with strong correlations are a major challenge for realistic electronic structure calculations. The complexity of the systems under consideration precludes a direct fully microscopic treatment by means of the theoretical and computational methods available at present. The present paper analyzes the applicability and restrictions of common approximation schemes by comparing their predictions for a model pertinent to heavy fermion metals to the exact solution. The criteria chosen for the assessment are the density distribution in the ground state as well as the energy scale for low-lying excitations.