  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.
