Compatibility of DFT+U with non-collinear magnetism and spin-orbit coupling

The extension of the DFT+U method to deal with non-collinear magnetism and spin-orbit coupling has been implemented in SIESTA, as reported in the following open-access publication:

Fernando Gómez-Ortiz, Nayara Carral-Sainz, James Sifuna, Virginia Monteseguro, Ramón Cuadrado, Pablo García-Fernández, and Javier Junquera: Compatibility of DFT+U with non-collinear magnetism and spin-orbit coupling within a framework of numerical atomic orbitals, Computer Physics Communications 286, 108684 (2023) .]

We have adapted the recipe given in the work by Bousquet and Spaldin [Phys. Rev. B 82, 220402 (2010)] to a formalism of numerical atomic orbitals. Both the Hubbard U and the exchange J parameter are explicitly included and treated separately. Only correlated electronic states in the d-orbitals are contemplated in this implementation.

This new functionality will be available in the next, forthcoming release of SIESTA, version 5.0 (preview available on the current development branch, for more information see the Guide to SIESTA versions).