How deeply are core electrons perturbed when valence electrons are spin polarized? The case study of transition metal compounds

© 2022 Wiley Periodicals LLC.

Bibliographische Detailangaben
Veröffentlicht in:Journal of computational chemistry. - 1984. - 44(2023), 2 vom: 15. Jan., Seite 65-75
1. Verfasser: Pascale, Fabien (VerfasserIn)
Weitere Verfasser: Doll, Klaus, Gentile, Francesco Silvio, Dovesi, Roberto
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2023
Zugriff auf das übergeordnete Werk:Journal of computational chemistry
Schlagworte:Journal Article Fermi contact constant KMnF3 perovskite comparison of the all electron effect of the adopted functional large core and small core results spin density function spin density profiles spin polarization of the inner shells
Beschreibung
Zusammenfassung:© 2022 Wiley Periodicals LLC.
The ferromagnetic and antiferromagnetic wave functions of the KMnF3 perovskite have been evaluated quantum-mechanically by using an all electron approach and, for comparison, pseudopotentials on the transition metal and the fluorine ions. It is shown that the different number of α and β electrons in the d shell of Mn perturbs the inner shells, with shifts between the α and β eigenvalues that can be as large as 6 eV for the 3s level, and is far from negligible also for the 2s and 2p states. The valence electrons of F are polarized by the majority spin electrons of Mn, and in turn, spin polarize their 1s electrons. When a pseudopotential is used, such a spin polarization of the core functions of Mn and F can obviously not take place. The importance of such a spin polarization can be appreciated by comparing (i) the spin density at the Mn and F nuclear position, and then the Fermi contact constant, a crucial quantity for the hyperfine coupling, and (ii) the ferromagnetic-antiferromagnetic energy difference, when obtained with an all electron or a pseudopotential scheme, and exploring how the latter varies with pressure. This difference is as large as 50% of the all electron datum, and is mainly due to the rigid treatment of the F ion core. The effect of five different functionals on the core spin polarization is documented
Beschreibung:Date Revised 29.11.2022
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1096-987X
DOI:10.1002/jcc.27015