Density functionals with spindensity accuracy for open shells
Abstract
Electrons in zero external magnetic field can be studied with the KohnSham (KS) scheme of either density functional theory (DFT) or spinDFT (SDFT). The latter is normally used for openshell systems because its approximations appear to model better the exchange and correlation (xc) functional, but also because, so far the application of DFT implied a closedshelllike approximation. In the first part of this Communication, we show that correcting this error for open shells allows the approximate DFT xc functionals to become as accurate as those in SDFT. In the second part, we consider the behavior of SDFT for zero magnetic field. We show that the KS equations of SDFT emerge as the generalized KS equations of DFT in this limit, thus establishing a so far unknown link between the two theories.
 Publication:

Journal of Chemical Physics
 Pub Date:
 March 2022
 DOI:
 10.1063/5.0071991
 arXiv:
 arXiv:2110.00969
 Bibcode:
 2022JChPh.156k1101C
 Keywords:

 Physics  Chemical Physics;
 Condensed Matter  Materials Science;
 Physics  Atomic and Molecular Clusters
 EPrint:
 doi:10.1063/5.0071991