Examination of self interaction correction methods for Na clusters

We examine whether the self interaction correction method by Harrison, which does not introduce the spherical single particle density approximation to energy functional, can be applied to Na clusters. We show that it does not work well, especially, for large clusters, though it works well for atomic systems. We suggest that it is better to apply this method only to the Hartree term. We also show that the effects of non-diagonal Lagrange multiplier originating from the orthonormality of single particle orbitals are negligible.