Comparison of self-interaction-corrections for metal clusters

We present a simple density-averaged approach to the self-interaction-correction (SIC) methods of density functional theory. We discuss both formal properties and applications, considering particularly metal clusters as test cases. We show that the density averaged ansatz exhibits crucial, original (as compared to other SIC schemes) properties such as unitary robustness and applicability to semi-classical approaches. It is ideally suited to systems with well defined length and energy scales such as simple metal clusters.