Hyperfine interactions for small systems including transition-metal elements using self-interaction corrected density-functional theory.

This article focuses on investigating magnetic hyperfine (HF) interactions in atomic systems and small molecules, including transition-metal (TM) elements such as titanium (Ti) and manganese (Mn), using the Fermi–Löwdin orbital (FLO) based self-interaction corrected (SIC) density-functional theory (DFT). The study calculates the Fermi contact (FC) and spin-dipole (SD) contributions to the HF coupling tensor within the local density approximation (LDA) and compares FLO-SIC results with those from standard LDA, generalized-gradient approximation (GGA), and experimental data. For atoms with atomic number Z ≤ 25 and TM-based molecules, FLO-SIC provides FC terms that better agree with experiments than SIC-free LDA or GGA, likely due to improved treatment of core spin polarization; for non-TM molecules, FLO-SIC accuracy is comparable to LDA and GGA. The work also examines basis set effects, finding that uncontracted basis sets have limited impact beyond the default FLO-SIC basis, which already adequately describes electron spin density near nuclei. These findings suggest FLO-SIC as a promising approach for more accurate HF interaction calculations in TM-containing systems relevant to quantum information science and magnetic property studies.