Self-interaction effects in the density functional description of iron(II) spin-crossover molecules

Spin-crossover metal complexes are one of the paradigmatic examples of magnetic molecular materials showing switching and bistability at the molecular level. Octahedral Fe2+ molecules are particularly interesting as they often exhibit such a spin-crossover transition. Many efforts were made to assess the performance of density functional theory for such systems. However an exchange-correlation functional able to account accurately for the energetic of the various possible spin-states has not been identified yet.
We present results on different Fe2+ ions using self-interaction corrected semilocal exchange-correlation functionals [1,2,3] within the FLO-SIC DFT framework and we focus on the energy differences between the various spin states. Further we compare our data to high level quantum chemical calculations.


[1] M. R. Pederson, A. Ruzsinszky, and J. P. Perdew, J. Chem. Phys. 140, 121103 (2014).
[2] M. R. Pederson, J. Chem. Phys. 142, 064112 (2015).
[3] T. Hahn, S. Liebing, J. Kortus, and M. R. Pederson, J. Chem. Phys. 43, 224104 (2015).