  We present one inherent shortcoming of the LDA+U method in respect of its
self-interaction correction of the LDA. By reexamining the mean-field
approximation on the Hubbard energy in the Hartree-Fock form, we have derived a
new expression for the ``double-counting'' energy which led to a more
reasonable self-interaction correction in an alternative LDA+U scheme. For the
bulk Gd metal, the new scheme resulted in electronic properties more consistent
with experiments in comparison to the LDA and the existing LDA+U schemes.
