1. Spin-orbit coupling from a two-component self-consistent approach. II. Non-collinear density functional theories
- Author
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Jacques K. Desmarais, Stanislav Komorovsky, Jean-Pierre Flament, Alessandro Erba, Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM), Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Università degli Studi di Torino, Dipartimento di Chimica, Torino
- Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[CHIM.POLY]Chemical Sciences/Polymers ,010304 chemical physics ,[CHIM.ANAL]Chemical Sciences/Analytical chemistry ,0103 physical sciences ,General Physics and Astronomy ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Physical and Theoretical Chemistry ,010306 general physics ,01 natural sciences - Abstract
International audience; We revise formal and numerical aspects of collinear and non-collinear density functional theories in the context of a two-component self-consistent treatment of spin–orbit coupling. Theoretical and numerical analyses of the non-collinear approaches confirm their ability to yield the proper collinear limit and provide rotational invariance of the total energy for functionals in the local-density or generalized-gradient approximations (GGAs). Calculations on simple molecules corroborate the formal considerations and highlight the importance of an effective screening algorithm to provide the sufficient level of numerical stability required for a rotationally invariant implementation of non-collinear GGA functionals. The illustrative calculations provide a first numerical comparison of both previously proposed non-collinear formulations for GGA functionals. The proposed screening procedure allows us to effectively deal with points of small magnetization, which would otherwise be problematic for the evaluation of the exchange–correlation energy and/or potential for non-collinear GGA functionals. Both previously suggested formulations for the non-collinear GGA are confirmed to be adequate for total energy calculations, provided that the screening is achieved on a sufficiently fine grid. All methods are implemented in the Crystal program.
- Published
- 2021