Construction of self-interaction-corrected exchange-correlation functionals within the correlation factor approach

To model the exchange-correlation hole rho(XC)(r, u) of Kohn-Sham theory, we employ the correlation factor ansatz, which has recently been developed in our group. In this ansatz, rho(XC)(r, u) is written as a product of the correlation factor f(C)(r, u) and an exchange-hole model rho(X)(r, u), i.e., rho(XC)(r, u) = f(C)(r, u)rho(X)(r, u). In particular, we address the one-electron, self-interaction error and introduce a modified correlation factor model where f(C)(r, u) is constructed such that it reduces identically to one in localized one-electron regions of a many-electron system. This self-interaction corrected exchange-correlation hole is then used to generate the corresponding exchange-correlation energy functional. The new functional is implemented into a Kohn-Sham program and assessed by calculating various molecular properties. We find that, overall, a significant improvement is obtained compared to previous versions of the correlation factor model. Published under license by AIP Publishing.