Self-interaction correction and isotropic hyperfine parameter of light atoms

Numerical self-consistent field (SCF) calculations in density functional theory (DFT) and the local spin-density approximation (LSDA) were performed for the light atoms H, Li, B, C, N, O and F, in order to investigate the effect of the self-interaction correction (SIC) on the isotropic (or contact) hyperfine parameter A _ISO. In contrast to the findings for certain 3d-metals and compounds, results for light-atom SI-corrected A _ISO present no improvement over the LSDA values. We show that relatively modest changes to the correlation potential can lead to significant improvement of densities near the nucleus and the related A _ISO, suggesting a direction for future improvements in DFT functionals.