Restoring the uniform density limit in Perdew-Zunger self-interaction correction

Abstract

The Perdew-Zunger self-interaction correction (PZ-SIC) makes approximate density functionals exact for all one-electron densities, but sacrifices exactness for uniform densities. I show that an alternative to the orbital density ansatz employed in PZ-SIC restores the uniform density limit. The new ansatz also eliminates the need to evaluate approximate density functionals on lobed one-electron densities extracted from smooth many-electron densities, thereby reducing orbital dependence and lobed density error. I demonstrate the alternative ansatz in a broadly accurate nonempirical locally scaled self-interaction-corrected generalized gradient approximation.