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

Area of Science:

• Computational Chemistry
• Quantum Information Science
• Condensed Matter Physics

Background:

• Magnetic hyperfine (HF) interactions are crucial for understanding magnetic materials and developing quantum information platforms.
• Accurate calculation of HF interactions is essential for theoretical and experimental advancements in these fields.

Purpose of the Study:

• To investigate magnetic hyperfine interactions in atomic and molecular systems using Fermi-Löwdin orbital (FLO) based self-interaction corrected (SIC) density-functional theory.
• To compare the accuracy of FLO-SIC with standard Local Density Approximation (LDA) and Generalized Gradient Approximation (GGA) methods against experimental data.

Main Methods:

• Employed Fermi-Löwdin orbital (FLO) based self-interaction corrected (SIC) density-functional theory.
• Calculated Fermi contact (FC) and spin-dipole terms for atomic systems (Z ≤ 25) and small molecules (including transition metals like Ti and Mn).
• Compared FLO-SIC results with LDA and GGA calculations and experimental data.

Main Results:

• For moderately heavy atoms, FLO-SIC achieved a mean absolute error of 27 MHz for the FC term, significantly lower than LDA and GGA.
• For transition-metal-based molecules, FLO-SIC showed a mean absolute error of 59 MHz, outperforming LDA (101 MHz) and GGA (82 MHz).
• For non-transition-metal molecules, FLO-SIC performance was comparable to LDA and GGA.

Conclusions:

• FLO-SIC density-functional theory provides more accurate predictions of magnetic hyperfine interactions for atomic and transition-metal systems compared to standard LDA and GGA.
• The improved accuracy of FLO-SIC is vital for advancing quantum information science and understanding magnetic properties.
• Core spin polarization can influence FC terms, leading to variations not always aligned with the expectation of increased spin density from SIC.