We extend some of the well established self-interaction correction (SIC) schemes of density-functional theory to the case of systems with noncollinear magnetism. Our proposed SIC schemes are tested on a set of molecules and metallic clusters in combination with the widely used local spin-density approximation. As expected from the collinear SIC, we show that the averaged-density SIC works well for improving ionization energies but fails to improve more subtle quantities like the dipole moments of polar molecules. We investigate the exchange-correlation magnetic field produced by our extension of the Perdew-Zunger SIC, showing that it is not aligned with the local total magnetization, thus producing an exchange-correlation torque.
@article{arxiv.2310.18321,
title = {Self-interaction correction schemes for non-collinear spin-density-functional theory},
author = {Nicolas Tancogne-Dejean and Martin Lüders and Carsten A. Ullrich},
journal= {arXiv preprint arXiv:2310.18321},
year = {2023}
}